Tumor Cells Of Origin Research Articles

Abstract 3100: Glial origin for MYCN-driven medulloblastoma and targeted prosenescence therapies

Abstract MYCN-amplified medulloblastoma is a poor-prognosis childhood brain tumor with unknown cellular origin. Recently, we showed how MYCN overexpression could generate tumors with high penetrance from a glutamate transporter (GLT1) promoter in a transgenic model (GTML) of medulloblastoma. By using Rosa26-lsl-LacZ reporters we also showed that GLT1-positive neural stem cells represent presumed cells of tumor origin. Transgenic GTML mice generate SHH-independent medulloblastoma 2-3 months after birth. Before tumor onset GTML mice presented significantly more proliferation in thalamic forebrain cells and in Bergmann glia in the cerebellum as compared to corresponding normal brain. Strikingly, adult GTML mice also show proliferative capacity in the Bergmann glia cell population in response to MYCN oncogene activity, further connecting this population to medulloblastoma development. Retroviral tagging using the RCAS/tv-a system marked BLBP- or GFAP-positive tumor initiating cells and expression analysis could further determine genetic profiles of glial origin. Interestingly, MYCN levels and early proliferation of brain tumors could be reduced by specific CDK2-inhibition by Milciclib or by using the bromodomain inhibitor JQ1. Treatment studies revealed a need for sustained treatment over 7-10 days to effectively abolish tumor cell proliferation. Both treatment strategies induced tumor cell senescence as seen by SA-beta-gal staining and by downregulated levels of Lamin B1. Our data suggest that tumors generated arise from radial glia or Bergmann glia in this medulloblastoma model and that dual inhibition of CDK2 and bromodomains suppresses tumor growth by targeting MYCN. Citation Format: Sara M. Bolin, Jasmine Lau, Justin Chen, Vasil Savov, Anders I. Persson, Sanna-Maria Hede, William A. Weiss, Fredrik Swartling. Glial origin for MYCN-driven medulloblastoma and targeted prosenescence therapies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3100. doi:10.1158/1538-7445.AM2014-3100

O4.01 * DISTINCT FUNCTIONAL ROLES OF WILD-TYPE EGFR AND ITS MUTANT EGFRVIII IN GLIOBLASTOMA DEVELOPMENT

The epidermal growth factor receptor (EGFR) is a well-known mediator of invasion, proliferation and survival of tumor cells. Amplification and associated overexpression of wild-type (wt) EGFR is the most common genetic alteration in primary glioblastoma (GBM), with a frequency of about 40-50%. Of the GBMs that have an amplification of EGFR, 50-60% also express the mutated EGFRvIII, which lacks the ligand-binding domain resulting in a constitutive activation of the receptor. It has been widely accepted that both wtEGFR and EGFRvIII substantially contribute to GBM pathogenesis, however, their specific in vivo functions are still a matter of debate. In this work we determined distinct functional roles of wtEGFR and the mutant EGFRvIII within human GBM cells in vivo. We genetically modified stem cell cultures of two different human GBM biopsies with low or absent wtEGFR expression to overexpress either wtEGFR or EGFRvIII. By orthotopic transplantation of the different cell-populations into the brains of immune-deficient rats, we were able to distinguish two different phenotypes based on MRI, histology/ immunohistochemistry and molecular analyses. Tumors with overexpression of wtEGFR showed an increased invasive growth pattern, while angiogenesis was either not observed or decreased compared to the original tumor cells. In contrast, EGFRviii overexpressing tumors were more angiogenic and less invasive compared to the control tumors and wtEGFR expressing tumors. Up-regulation of HIF1A as well as a panel of angiogenic factors confirmed angiogenesis in EGFRvIII overexpressing tumors. Integrated bioinformatics of microarray and proteomics data point to differences in signaling pathway activation between wtEGFR and EGFRvIII. In conclusion, our results demonstrate contrasting roles of wtEGFR and its mutant EGFRvIII in invasion and angiogenesis and suggest a concerted action of both receptors to promote the aggressive phenotype of human GBM in vivo.

MiR-141 and miR-200c as markers of overall survival in early stage non-small cell lung cancer adenocarcinoma.

BackgroundSeveral treatments in non-small cell lung cancer (NSCLC) are histology-dependent, and the need for histology-related markers is increasing. MicroRNAs (miRNAs) are promising molecular markers in multiple cancers and show differences in expression depending on histological subtype. The miRNA family miR-200 has been associated with the regulation of epithelial-mesenchymal (EMT)/mesenchymal-epithelial transition (MET). EMT involves profound phenotypic changes that include the loss of cell-cell adhesion, the loss of cell polarity, and the acquisition of migratory and invasive properties that facilitates metastasis. A dual role for the miR-200 family in the prognosis of several tumors has been related to tumor cell origin. However, the prognostic role and function of miR-200 family in early-stage NSCLC adenocarcinoma and squamous cell carcinoma (SCC) have not been well established.MethodsmiRNA expression was determined using TaqMan assays in 155 tumors from resected NSCLC patients. Functional studies were conducted in three NSCLC cell lines: H23, A-549 and HCC-44.ResultsHigh miR-200c expression was associated with shorter overall survival (OS) in the entire cohort (p = 0.024). High miR-200c (p = 0.0004) and miR-141 (p = 0.009) expression correlated with shorter OS in adenocarcinoma – but not in SCC. In the multivariate analysis, a risk score based on miR-141 and miR-200c expression emerged as an independent prognostic factor for OS in the entire cohort (OR, 2.787; p = 0.033) and in adenocarcinoma patients (OR, 10.649; p = 0.002). Functional analyses showed that miR-200c, was related to mesenchymal-epithelial transition (MET) and affected cell migration and E-cadherin levels, while overexpression of miR-141 reduced KLF6 protein levels and produced an increase of secretion of VEGFA in vitro (H23, p = 0.04; A-549, p = 0.03; HCC-44, p = 0.02) and was associated with higher blood microvessel density in patient tumor samples (p<0.001).ConclusionHigh miR-141 and miR-200c expression are associated with shorter OS in NSCLC patients with adenocarcinoma through MET and angiogenesis.

VASCULOGENESIS IN VON HIPPEL-LINDAU DISEASE ASSOCIATED TUMORS

BACKGROUND: Emerging data indicate that von Hippel-Lindau disease (VHL) associated tumors arise from embryologic hemangioblasts that can form vessels (endothelial cells) and blood cells. Nevertheless, the origin of VHL-associated vasculature is not known. To determine the origin of VHL-associated tumor vasculature, we investigated the neoplastic vasculature from VHL patients. METHODS: Microdissected VHL-associated tumor (compared to control non-VHL tissues) vascular features were examined using immunohistochemical staining for CA9, HIF-2a, HIF-1a, CD31 and Factor VIIIa. Origin of tumor vascular elements (tumor versus non-tumor) was assessed by LOH and FISH analysis. Intratumoral vasculogenesis was assessed in vivo using the VHL-deficient UMRC6 renal carcinoma murine xenograft model. RESULTS: We demonstrate that isolated vascular structures and blood vessels within VHL-associated neoplasms (including hemangioblastomas, renal cell carcinoma and pancreatic tumors) are a result of tumor-derived vasculogenesis. Further, similar to hemangioblastomas, other VHL-associated neoplasms possess vascular tissue of tumor origin. Similarly, tumor-derived endothelial cells emerge within implanted VHL deficient UMRC6 renal cell carcinoma murine xenografts. CONCLUSIONS: These findings further establish the embryologic, developmentally arrested, hemangioblast as the tumor cell of origin for VHL-associated hemangioblastomas and indicate that it is also the progenitor cell for other VHL-associated tumors. SECONDARY CATEGORY: Neuropathology & Tumor Biomarkers.

The adenocarcinoma cell surface mucin receptor for alpha-fetoprotein: is the same receptor present on circulating monocytes and macrophages? A commentary.

The mucin family of proteins is largely expressed on sedentary epithelial cells lining the gastrointestinal, pulmonary, and reproductive tracts and their associated organs and malignant tumors. It is less well-known that mucins are also expressed on circulatory cells of the immune and inflammatory systems, such as monocytes, macrophages, leukemic, and lymphoma cells. The epithelial mucins function in (a) protection and lubrication of mucosal linings, (b) cell adhesion and cell-to-cell contact, (c) cell migration and metastasis, and (d) signal transduction. It would be logical to presume that mucins expressed on circulating mononuclear cells could perform similar functions. Recently, it was proposed that the alpha-fetoprotein (AFP) receptor, known to be present on solid epithelial-derived malignant tumor cells, can be identified as a mucin glycoprotein. Interestingly, it was also reported that AFP binds to a receptor on circulating cells and sedentary tumor cells of lymphoreticular origin, especially monocytes associated with lymphomas and leukemias. The primary objective of the present commentary is to present literature-based evidence that some of the cell surface mucins on sedentary epithelial tumor cells and certain mucins expressed on circulating monocytes/macrophages are identical to the AFP receptor. The secondary objective is to discuss the role of AFP and its derived peptides in the growth suppression of adenocarcinomas and lymphomas using the AFP-mucin receptor concept as a key to the mechanism of tumor growth inhibition.

Evidence for pericyte origin of TSC-associated renal angiomyolipomas and implications for angiotensin receptor inhibition therapy.

Nearly all patients with tuberous sclerosis complex (TSC) develop renal angiomyolipomas, although the tumor cell of origin is unknown. We observed decreased renal angiomyolipoma development in patients with TSC2- polycystic kidney disease 1 deletion syndrome and hypertension that were treated from an early age with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers compared with patients who did not receive this therapy. TSC-associated renal angiomyolipomas expressed ANG II type 1 receptors, platelet-derived growth factor receptor-β, desmin, α-smooth muscle actin, and VEGF receptor 2 but did not express the adipocyte marker S100 or the endothelial marker CD31. Sera of TSC patients exhibited increased vascular mural cell-secreted peptides, such as VEGF-A, VEGF-D, soluble VEGF receptor 2, and collagen type IV. These findings suggest that angiomyolipomas may arise from renal pericytes. ANG II treatment of angiomyolipoma cells in vitro resulted in an exaggerated intracellular Ca(2+) response and increased proliferation, which were blocked by the ANG II type 2 receptor antagonist valsartan. Blockade of ANG II signaling may have preventative therapeutic potential for angiomyolipomas.

Recent syntheses and biological activity of lentiginosine and its analogues.

(+)-Lentiginosine, a natural trans-1,2-dihydroxyindolizidine belonging to the class of iminosugars, is a potent inhibitor of amyloglucosidase, and a good inhibitor of Hsp90. The non-natural enantiomer, (-)-lentiginosine, induces apoptosis on tumor cells of different origin and is poorly cytotoxic towards non-transformed cells. The significant biological activity of these compounds has resulted in the development of many synthetic approaches for their preparation. This review is an update of a previous survey and summarizes the most recent achievements on biological studies as well as total syntheses of lentiginosine and trans-1,2-dihydroxyindolizidine analogues.

Comparision influence of conditioned medium of human mesenchimal cells and interferon-α on development of tumor cell population

This work is a study of mediators and mechanisms of the effect of human mesenchymal stem cells from bone marrow (hMSC BM) on the tumor cell population line MCF-7 (breast adenocarcinoma). It is known that MSCs produce a wide range of cytokines and chemokines, and provide humoral cells interaction. BM MSCs produce tumor necrosis factor (TNF-α), interleukin (IL-1β, IL-2, IL-4, IL-6, IL-8), interferon-alpha (IFN-α). In this study we compared the proliferation, adhesion, survival and antigenic profile of breast adenocarcinoma cells that were cultured with conditioned medium (с-medium) of the MSC and IFN-α. Consequently, it was found that с-medium from MSC inhibited proliferation activity of MCF-7, increased cells adhesion, suppressed the ability to migrate, and reduced the expression of estrogen receptor and epidermal growth factor receptor. Conversely expression of cytokeratins increased, which is a positive sign for the tumor cells of epithelial origin. IFN-α showed a more pronounced effect on the tumor population. These findings suggest that cryopreserved MSC BM has antitumor activity. Also, our data suggest that IFN-alpha is one of the mediators of antitumor effect of MSCs.

Su1998 Effects of Alternative Xeno-Free Media Formulations on the Functional Characteristics of IFN-γ-Primed Human Bone Marrow and Adipose Derived Mesenchymal Stem Cells

Background: The role of gastrointestinal Dclk1 is an emerging topic of intense interest and debate. Recent reports have now established that Dclk1 is primarily expressed in epithelial tuft cells and are the cell of origin for tumors in Apc mice. Moreover Dclk1-intestinalepithelial-deficientVillin-Cre;Dclk1mice demonstratedmarked gene expression changes in pathways critical to epithelial growth, stemness, barrier function, and taste reception signaling at homeostasis. Following genotoxic injury the Villin-Cre;Dclk1 mice failed to maintain tight junctions and died significantly sooner. An examination of Lgr5 and its companion genes Ascl2 and Smoc2 mRNA levels following genotoxic injury revealed a clear suppression of all three genes throughout. These published findings suggest that Dclk1 plays a functional role within the epithelia, likely through chemosensing. We wanted to explore whether the ablation of Dclk1 within the mesenchyme could impact the epithelia through disruption of inter-compartmental interaction mediated by Dclk1. To accomplish this we utilized the gastrointestinal mesenchyme specific promoter Foxl1-Cre (provided by Dr. K. Kaestner). As a means of exacerbating epithelial restitution, we utilized the radiation injury model, which is exceptional as a surrogate for studying the principles of epithelial restitution. Aim: To determine the functional role mesenchymal Dclk1 under the control of the Foxl1Cre promoter at homeostasis and following genotoxic injury. Methods: To evaluate what function mesenchymal Dclk1 might serve to the epithelia proper, we first created the novel compound mouse Foxl1-Cre;Dclk1 and examined for morphologic alterations or molecular changes (i.e. RT-PCR, WB, IHC) to prominent intestinal epithelial markers (e.g. Dclk1, Lgr5, BMI1, Cox1, and chemosensory genes) at homeostasis and following radiation exposure sufficient to cause crypt loss and initiate a restorative response, when compared to Foxl1-Cre littermates (n=10). Results: The initial examination of tissues from the Dclk1mesenchymal-defient Foxl1-Cre;Dclk1 mice at homeostasis revealed a dramatic upregulation of epithelial tuft cells (~10-fold) as identified by both Dclk1 and Cox1 immunostaining. Once radiation studies are complete, we will determine whether the net gain so many Dclk1+ tuft cells can provide any relief from the radiosensitivity seen in the intestines of Dclk1tuft cell containing mice and evaluate their ultimate outcome. Conclusions: Ablation of Dclk1 within the mesenchyme has a clear and dramatic effect upon the intestinal epithelial tuft cell production. We predict that this is a compensatory attempt by the epithelium in the absence of a complete inter-compartmental cellular sensory scheme. These findings indicate that mesenchymal Dclk1 has a significant responsibility in epithelial function.

Su1997 Ablation of Mesenchymal DCLK1 by the Foxl1-Cre Promoter Results in Increased Epithelial Tuft Cells

Background: The role of gastrointestinal Dclk1 is an emerging topic of intense interest and debate. Recent reports have now established that Dclk1 is primarily expressed in epithelial tuft cells and are the cell of origin for tumors in Apc mice. Moreover Dclk1-intestinalepithelial-deficientVillin-Cre;Dclk1mice demonstratedmarked gene expression changes in pathways critical to epithelial growth, stemness, barrier function, and taste reception signaling at homeostasis. Following genotoxic injury the Villin-Cre;Dclk1 mice failed to maintain tight junctions and died significantly sooner. An examination of Lgr5 and its companion genes Ascl2 and Smoc2 mRNA levels following genotoxic injury revealed a clear suppression of all three genes throughout. These published findings suggest that Dclk1 plays a functional role within the epithelia, likely through chemosensing. We wanted to explore whether the ablation of Dclk1 within the mesenchyme could impact the epithelia through disruption of inter-compartmental interaction mediated by Dclk1. To accomplish this we utilized the gastrointestinal mesenchyme specific promoter Foxl1-Cre (provided by Dr. K. Kaestner). As a means of exacerbating epithelial restitution, we utilized the radiation injury model, which is exceptional as a surrogate for studying the principles of epithelial restitution. Aim: To determine the functional role mesenchymal Dclk1 under the control of the Foxl1Cre promoter at homeostasis and following genotoxic injury. Methods: To evaluate what function mesenchymal Dclk1 might serve to the epithelia proper, we first created the novel compound mouse Foxl1-Cre;Dclk1 and examined for morphologic alterations or molecular changes (i.e. RT-PCR, WB, IHC) to prominent intestinal epithelial markers (e.g. Dclk1, Lgr5, BMI1, Cox1, and chemosensory genes) at homeostasis and following radiation exposure sufficient to cause crypt loss and initiate a restorative response, when compared to Foxl1-Cre littermates (n=10). Results: The initial examination of tissues from the Dclk1mesenchymal-defient Foxl1-Cre;Dclk1 mice at homeostasis revealed a dramatic upregulation of epithelial tuft cells (~10-fold) as identified by both Dclk1 and Cox1 immunostaining. Once radiation studies are complete, we will determine whether the net gain so many Dclk1+ tuft cells can provide any relief from the radiosensitivity seen in the intestines of Dclk1tuft cell containing mice and evaluate their ultimate outcome. Conclusions: Ablation of Dclk1 within the mesenchyme has a clear and dramatic effect upon the intestinal epithelial tuft cell production. We predict that this is a compensatory attempt by the epithelium in the absence of a complete inter-compartmental cellular sensory scheme. These findings indicate that mesenchymal Dclk1 has a significant responsibility in epithelial function.

Antitumor phosphate-containing lipids and non-phosphorus alkyl cationic glycerolipids: chemical structures and perspectives of drug development

Candidates to antitumor drugs of lipid nature are reviewed. The biological effects of the following known antineoplastic phosphate-containing lipids are described: edelfosine, ilmofosine, milfosine, perifosine, and erufosine. Although the most active phosphate-containing lipid edelfosine causes the death of tumor cells of different tissue origin, it possesses a strong hemolytic effect and toxicity toward non-malignant counterparts. The phosphate-containing lipids can be inactivated by phospholipases, which gave rise to the search for the optimum structure of cationic glycerolipids containing no phosphate group and having a similar antitumor activity. The results of structural functional studies of the non-phosphorus cationic glycerolipids with the best antitumor activity are generalized.

Involvement of tumor-associated macrophage activation in vitro during development of a novel mantle cell lymphoma cell line, PF-1, derived from a typical patient with relapsed disease

Human mantle cell lymphoma (MCL) cell lines are scarce and have been only sporadically described and validated, and only a few have been thoroughly molecularly or genetically characterized. We describe here the successful establishment of a new MCL line, PF-1, with typical MCL characteristics. Culturing primary MCL cells in vitro initially gave rise to an essential generative microenvironment “niche” involving macrophages required for MCL growth, and eventually produced the PF-1 MCL cell line. Our analysis revealed that PF-1 is morphologically and genotypically nearly identical to the original tumor cells. The PF-1 MCL cell line that we have developed will be useful for in vitro and in vivo studies of MCL pathogenesis and therapeutics.

The Adult Macaque Spinal Cord Central Canal Zone Contains Proliferative Cells And Closely Resembles The Human

The persistence of proliferative cells, which could correspond to progenitor populations or potential cells of origin for tumors, has been extensively studied in the adult mammalian forebrain, including human and nonhuman primates. Proliferating cells have been found along the entire ventricular system, including around the central canal, of rodents, but little is known about the primate spinal cord. Here we describe the central canal cellular composition of the Old World primate Macaca fascicularis via scanning and transmission electron microscopy and immunohistochemistry and identify central canal proliferating cells with Ki67 and newly generated cells with bromodeoxyuridine incorporation 3 months after the injection. The central canal is composed of uniciliated, biciliated, and multiciliated ependymal cells, astrocytes, and neurons. Multiciliated ependymal cells show morphological characteristics similar to multiciliated ependymal cells from the lateral ventricles, and uniciliated and biciliated ependymal cells display cilia with large, star-shaped basal bodies, similar to the Ecc cells described for the rodent central canal. Here we show that ependymal cells with one or two cilia, but not multiciliated ependymal cells, proliferate and give rise to new ependymal cells that presumably remain in the macaque central canal. We found that the infant and adult human spinal cord contains ependymal cell types that resemble those present in the macaque. Interestingly, a wide hypocellular layer formed by bundles of intermediate filaments surrounded the central canal both in the monkey and in the human, being more prominent in the stenosed adult human central canal.

Detection of circulating tumor cells in the cerebrospinal fluid of a patient with a solitary metastasis from breast cancer: A case report.

Brain lesions identified following the diagnosis and eradication of primary cancers are often ambiguous in origin, existing as a solitary metastasis or an independent primary brain tumor. The brain is a relatively common site of metastasis with breast cancer, although determining whether metastases have originated from the breast or brain is often not possible without invasive biopsies. In the current case report, a patient presented with a brain lesion identified by radiography and was without systemic disease. The patient had previously exhibited a complete response to chemotherapy and surgery for a poorly differentiated invasive ductal carcinoma. The origin of the brain lesion could not be determined by magnetic resonance imaging, giving rise to a diagnostic dilemma with diverging treatment options. We previously reported a method to isolate and enumerate tumor cells of epithelial origin in the cerebrospinal fluid (CSF). CSF tumor cell analysis of the patient revealed massive CSF tumor cell burden of epithelial origin, indicating that the brain lesion was likely of breast origin. The current case report highlights the use of CSF tumor cell detection as a differential diagnostic tool, in addition to its previously demonstrated use as a marker of disease burden and therapeutic response.

Can There be a Place for Intraoperative Salvaged Blood in Spine Tumor Surgery?

Intraoperative cell salvage (IOCS) has been used in musculoskeletal surgery extensively. However, it has never found its place in musculoskeletal oncologic surgery. We have conducted the first-ever study to evaluate the feasibility of IOCS in combination with a leucocyte-depletion filter (LDF) in metastatic spine tumor surgery. This was to pave the path for use of IOCS-LDF in musculoskeletal oncologic surgery. Patients with a known primary epithelial tumor, who were offered surgery for metastatic spinal disease, were recruited. Blood samples were collected at three different stages during the surgery: from the operative field before IOCS processing, after IOCS processing, and after IOCS-LDF processing. Three separate samples (5 mL each) were taken at each stage. Samples were examined using immunohistochemical monoclonal antibodies to identify tumor cells of epithelial origin. Of 30 patients in the study, 6 were excluded for not fulfilling the inclusion criteria, leaving 24 patients. Malignant tumor cells were detected in the samples from the operative field before IOCS processing in eight patients and in the samples from the transfusion bag after IOCS processing in three patients. No viable malignant cell was detectable in any of the blood samples after passage through both IOCS and LDF. The findings support the notion that the IOCS-LDF combination works effectively in eliminating tumor cells from salvaged blood, so this technique can be applied successfully in spine tumor surgery. This concept can then further be extended to whole musculoskeletal tumor surgery and other oncologic surgeries with further appropriate clinical studies.

Tumor derived vasculogenesis in von Hippel-Lindau disease-associated tumors

von Hippel-Lindau disease (VHL) patients develop highly vascular tumors, including central nervous system hemangioblastomas. It has been hypothesized that the vascular nature of these tumors is the product of reactive angiogenesis. However, recent data indicate that VHL-associated hemangioblastoma neoplastic cells originate from embryologically-arrested hemangioblasts capable of blood and endothelial cell differentiation. To determine the origin of tumor vasculature in VHL-associated hemangioblastomas, we analyzed the vascular elements in tumors from VHL patients. We demonstrate that isolated vascular structures and blood vessels within VHL-associated hemangioblastomas are a result of tumor-derived vasculogenesis. Further, similar to hemangioblastomas, we demonstrate that other VHL-associated lesions possess vascular tissue of tumor origin and that tumor-derived endothelial cells emerge within implanted VHL deficient UMRC6 RCC murine xenografts. These findings further establish the embryologic, developmentally arrested, hemangioblast as the tumor cell of origin for VHL-associated hemangioblastomas and indicate that it is also the progenitor cell for other VHL-associated tumors.

Mechanical properties of fibroblasts depend on level of cancer transformation

Recently, it was revealed that tumor cells are significantly softer than normal cells. Although this phenomenon is well known, it is connected with many questions which are still unanswered. Among these questions are the molecular mechanisms which cause the change in stiffness and the correlation between cell mechanical properties and their metastatic potential. We studied mechanical properties of cells with different levels of cancer transformation. Transformed cells in three systems with different transformation types (monooncogenic N-RAS, viral and cells of tumor origin) were characterized according to their morphology, actin cytoskeleton and focal adhesion organization. Transformation led to reduction of cell spreading and thus decreasing the cell area, disorganization of actin cytoskeleton, lack of actin stress fibers and decline in the number and size of focal adhesions. These alterations manifested in a varying degree depending on type of transformation. Force spectroscopy by atomic force microscopy with spherical probes was carried out to measure the Young's modulus of cells. In all cases the Young's moduli were fitted well by log-normal distribution. All the transformed cell lines were found to be 40–80% softer than the corresponding normal ones. For the cell system with a low level of transformation the difference in stiffness was less pronounced than for the two other systems. This suggests that cell mechanical properties change upon transformation, and acquisition of invasive capabilities is accompanied by significant softening.

Y-chromosome status identification suggests a recipient origin of posttransplant non-small cell lung carcinomas: chromogenic in situ hybridization analysis.

Owing to the need of lifelong immunosuppression, solid-organ transplant recipients are known to have an increased risk of posttransplant malignancies including lung cancer. Posttransplant neoplastic transformation of donor-derived cells giving rise to hematopoietic malignancies, Kaposi sarcoma, and basal cell carcinoma in nongraft tissues has been reported. The goal of this study was to assess the cell origin (donor versus recipient derived) of posttransplant non-small cell lung carcinomas (NSCLCs) in kidney and heart transplant recipients. An institutional database search identified 2557 kidney and heart transplant recipients in 8 consecutive years. Among this cohort, 20 (0.8%) renal and 18 (0.7%) heart transplant recipients developed NSCLC. The study cohort comprised 6 of 38 NSCLCs arising in donor-recipient sex-mismatched transplant patients. The tumor cell origin was evaluated by chromogenic in situ hybridization with Y-chromosome probe on formalin-fixed, paraffin-embedded tissues. Y-chromosome was identified in 97% ± 1% (range from 92% to 99%) of all types of nucleated cells in male control tissues. In all 5 NSCLCs from male recipients of female donor organ, Y-chromosome was identified in 97% ± 2% (range from 92% to 100%) of tumor cells, statistically equivalent to normal control (P < .001). No Y-chromosome was identified in NSCLC cells from a female recipient of male kidney. These findings suggest a recipient derivation of NSCLC arising in kidney and heart transplant recipients. A combination of histologic evaluation and chromogenic in situ hybridization with Y-chromosome analysis allows reliable determination of tissue origin in sex-mismatched solid-organ transplant recipients and may aid in management of posttransplant malignancy in such cases.

Expression of chromobox homolog 7 (CBX7) is associated with poor prognosis in ovarian clear cell adenocarcinomaviaTRAIL-induced apoptotic pathway regulation

Ovarian cancer is the most lethal gynecologic malignancy, and clear cell adenocarcinoma of the ovary (OCCA), in particular, has a relatively poor prognosis among the ovarian cancer subtypes because of its high chemoresistance. Chromobox (CBX) 7 is a polycomb repressive complex 1 component that prolongs the lifespan of normal human cells by downregulating the INK4a/ARF expression which promotes cell-cycle progression. However, recent reports studying the relationship between CBX7 expression and patient survival have differed regarding the tumor cell origins, and the precise role of CBX7 in human carcinomas remains obscure. In this study, we analyzed CBX7 expression by immunohistochemistry in 81 OCCA patients and evaluated its association with their clinical outcomes. Both the overall and progression-free survival rates of the CBX7-positive patients were significantly shorter than those of the CBX7-negative patients (p < 0.05). CBX7 knockdown experiments using two OCCA cell lines, TOV21G and KOC-7C, revealed that cell viability was significantly reduced compared to the control cells (p < 0.001). Expression microarray analysis revealed that apoptosis-related genes, particularly tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were significantly upregulated in CBX7 knockdown cells (p < 0.01). We further confirmed that CBX7 knockdown resulted in TRAIL-induced apoptosis in the OCCA cells. Thus, in this study, we showed for the first time that CBX7 was associated with a decreased OCCA prognosis. We also successfully demonstrated that the TRAIL pathway is a novel target for CBX7 expression modulation in these cells, and therapeutic agents utilizing the TRAIL pathway may be particularly effective for targeted OCCA therapy.

The novel steroidal alkaloids dendrogenin A and B promote proliferation of adult neural stem cells

Dendrogenin A (DDA) and dendrogenin B (DDB) are new aminoalkyl oxysterols which display re-differentiation of tumor cells of neuronal origin at nanomolar concentrations. We analyzed the influence of dendrogenins on adult mice neural stem cell proliferation, sphere formation and differentiation. DDA and DDB were found to have potent proliferative effects in neural stem cells. Additionally, they induce neuronal outgrowth from neurospheres during in vitro cultivation. Taken together, our results demonstrate a novel role for dendrogenins A and B in neural stem cell proliferation and differentiation which further increases their likely importance to compensate for neuronal cell loss in the brain.