Platelet microRNAs inhibit primary tumor growth via broad modulation of tumor cell mRNA expression in ectopic pancreatic cancer in mice

We investigated the contributions of platelet microRNAs (miRNAs) to the rate of growth and regulation of gene expression in primary ectopic tumors using mouse models. We previously identified an inhibitory role for platelets in solid tumor growth, mediated by tumor infiltration of platelet microvesicles (microparticles) which are enriched in platelet-derived miRNAs. To investigate the specific roles of platelet miRNAs in tumor growth models, we implanted pancreatic ductal adenocarcinoma cells as a bolus into mice with megakaryocyte-/platelet-specific depletion of mature miRNAs. We observed an ~50% increase in the rate of growth of ectopic primary tumors in these mice compared to controls including at early stages, associated with reduced apoptosis in the tumors, in particular in tumor cells associated with platelet microvesicles—which were depleted of platelet-enriched miRNAs—demonstrating a specific role for platelet miRNAs in modulation of primary tumor growth. Differential expression RNA sequencing of tumor cells isolated from advanced primary tumors revealed a broad cohort of mRNAs modulated in the tumor cells as a function of host platelet miRNAs. Altered genes comprised 548 up-regulated transcripts and 43 down-regulated transcripts, mostly mRNAs altogether spanning a variety of growth signaling pathways–notably pathways related to epithelial-mesenchymal transition—in tumor cells from platelet miRNA-deleted mice compared with those from control mice. Tumors in platelet miRNA-depleted mice showed more sarcomatoid growth and more advanced tumor grade, indicating roles for host platelet miRNAs in tumor plasticity. We further validated increased protein expression of selected genes associated with increased cognate mRNAs in the tumors due to platelet miRNA depletion in the host animals, providing proof of principle of widespread effects of platelet miRNAs on tumor cell functional gene expression in primary tumors in vivo. Together, these data demonstrate that platelet-derived miRNAs modulate solid tumor growth in vivo by broad-spectrum restructuring of the tumor cell transcriptome.

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Platelet microparticles infiltrating solid tumors transfer miRNAs that suppress tumor growth

Blood ◽

10.1182/blood-2016-11-751099 ◽

2017 ◽

Vol 130 (5) ◽

pp. 567-580 ◽

Cited By ~ 87

Author(s):

James V. Michael ◽

Jeremy G. T. Wurtzel ◽

Guang Fen Mao ◽

A. Koneti Rao ◽

Mikhail A. Kolpakov ◽

...

Keyword(s):

Tumor Growth ◽

Tumor Cell ◽

Solid Tumors ◽

Tumor Cells ◽

Solid Tumor ◽

Solid Tumor Growth ◽

Key Points ◽

Platelet Microparticles

Key Points Platelet MPs infiltrate solid tumors and transfer platelet-derived miRNAs to tumor cells within solid tumors in vivo. Transfer of platelet miRNAs to tumor cells results in downregulation of tumor cell genes and inhibition of solid tumor growth.

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Genetic tagging of tumor cells with retrovirus vectors: clonal analysis of tumor growth and metastasis in vivo.

Molecular and Cellular Biology ◽

10.1128/mcb.8.8.3143 ◽

1988 ◽

Vol 8 (8) ◽

pp. 3143-3149 ◽

Cited By ~ 28

Author(s):

B Korczak ◽

I B Robson ◽

C Lamarche ◽

A Bernstein ◽

R S Kerbel

Keyword(s):

Tumor Growth ◽

Tumor Cell ◽

Primary Tumor ◽

Lung Metastases ◽

Mammary Adenocarcinoma ◽

Cell Populations ◽

Primary Tumors ◽

Large Numbers ◽

Retrovirus Vector

Retrovirus vector infection was used to introduce large numbers of unique genetic markers into tumor cell populations for the purpose of analyzing comparative changes in the clonal composition of metastatic versus that of nonmetastatic tumors during their progressive growth in vivo. The cell lines used were SP1, a nonmetastatic, aneuploid mouse mammary adenocarcinoma, and SP1HU9L, a metastatic variant of SP1. Cells were infected with delta e delta pMoTN, a replication-defective retrovirus vector which possesses the dominant selectable neo gene and crippled long terminal repeats. G418r colonies were obtained at a frequency of 4 x 10(-3). Southern blot analysis of a number of clones provided evidence of random and heritable integration of one or two copies of the proviral DNA. Clonal evolution of primary tumor growth and the nature of lineage relationships among spontaneous metastases and primary tumors were analyzed by subcutaneously injecting 10(5) cells from a pooled mixture of 3.6 x 10(2) G418r SP1HU9L or 10(4) G418r SP1 colonies into syngeneic CBA/J mice. The most striking finding was the relative clonal homogeneity of advanced primary tumors; they invariably consisted of a small number (less than 10) of distinct clones despite the fact that hundreds or thousands of uniquely marked clones had been injected. In the case of the metastatic SP1HU9L cells, the nature of these "dominant" clones varied from one tumor to another. Analysis of a number of lung metastases revealed that a proportion of them were derived from dominant primary tumor clones and were composed of one, and sometimes two, distinct progenitors. In some animals, all the lung metastases were derived from a common progenitor clone, whereas in others, each metastatic nodule had a different progenitor. The results show the following. (i) Retrovirus vector infection can be used to introduce large numbers of unique and stable clonal markers into tumor cell populations. (ii) The progeny of a very limited number of clones dominate in advanced primary tumors. (iii) Mammary carcinoma metastases are of mono- or biclonal origin. The significance of the results is discussed.

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Genetic tagging of tumor cells with retrovirus vectors: clonal analysis of tumor growth and metastasis in vivo

Molecular and Cellular Biology ◽

10.1128/mcb.8.8.3143-3149.1988 ◽

1988 ◽

Vol 8 (8) ◽

pp. 3143-3149

Author(s):

B Korczak ◽

I B Robson ◽

C Lamarche ◽

A Bernstein ◽

R S Kerbel

Keyword(s):

Tumor Growth ◽

Tumor Cell ◽

Primary Tumor ◽

Lung Metastases ◽

Mammary Adenocarcinoma ◽

Cell Populations ◽

Primary Tumors ◽

Large Numbers ◽

Retrovirus Vector

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Depleting RhoA/Stress Fiber-Organized Fibronectin Matrices on Tumor Cells Non-Autonomously Aggravates Fibroblast-Driven Tumor Cell Growth

International Journal of Molecular Sciences ◽

10.3390/ijms21218272 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8272

Author(s):

Li-Tzu Huang ◽

Chen-Lung Tsai ◽

Shin-Huei Huang ◽

Ming-Min Chang ◽

Wen-Tsan Chang ◽

...

Keyword(s):

Cell Proliferation ◽

Cell Growth ◽

Tumor Growth ◽

Tumor Cell ◽

Tumor Cells ◽

Stress Fiber ◽

Tumor Cell Growth ◽

Primary Tumor Growth

Fibronectin (FN) expressed by tumor cells has been known to be tumor suppressive but the pericellular FN (periFN) assembled on circulating tumor cells appears to evidently promote distant metastasis. Whereas the regulation of periFN assembly in suspended cells has currently been under investigation, how it is regulated in adherent tumor cells and the role of periFN in primary tumor growth remain elusive. Techniques of RNAi, plasmid transfections, immunoblotting, fluorescence/immunohistochemistry staining, cell proliferation assays, and primary tumor growth in C57BL6 mice and Fischer 344 rats were employed in this study. We found that endogenously synthesized FN in adherent tumor cells was required for periFN assembly which was aligned by RhoA-organized actin stress fiber (SF). Depleting periFN on adherent tumor cells congruently promoted in vivo tumor growth but surprisingly did not autonomously impact on in vitro tumor cell proliferation and apoptosis, suggestive of a non-autonomous role of periFN in in vivo tumor growth. We showed that the proliferative ability of shFN-expressing tumor cells was higher than shScramble cells did in the presence of fibroblasts. Altogether, these results suggested that depriving RhoA/SF-regulated periFN matrices non-autonomously promotes fibroblast-mediated tumor cell growth.

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Photo-Electro Active Nanocomposite Silk Hydrogel for Spatiotemporal Controlled Release of Chemotherapeutics: An In Vivo Approach toward Suppressing Solid Tumor Growth

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c02470 ◽

2020 ◽

Vol 12 (25) ◽

pp. 27905-27916 ◽

Cited By ~ 2

Author(s):

Ankit Gangrade ◽

Basveshwar Gawali ◽

Praveen Kumar Jadi ◽

Vegi G. M. Naidu ◽

Biman B. Mandal

Keyword(s):

Controlled Release ◽

Tumor Growth ◽

Solid Tumor ◽

Solid Tumor Growth ◽

Silk Hydrogel

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Tumor quiescence: elevating SOX2 in diverse tumor cell types downregulates a broad spectrum of the cell cycle machinery and inhibits tumor growth

BMC Cancer ◽

10.1186/s12885-020-07370-7 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Ethan P. Metz ◽

Erin L. Wuebben ◽

Phillip J. Wilder ◽

Jesse L. Cox ◽

Kaustubh Datta ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Tumor Growth ◽

Tumor Cell ◽

Tumor Cells ◽

Molecular Mechanisms ◽

Cell Types ◽

Cell Cycle Machinery

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.

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Role of mTOR in solid tumor systems: a therapeutical target against primary tumor growth, metastases, and angiogenesis

Cancer and Metastasis Reviews ◽

10.1007/s10555-007-9077-8 ◽

2007 ◽

Vol 26 (3-4) ◽

pp. 611-621 ◽

Cited By ~ 75

Author(s):

Hendrik Seeliger ◽

Markus Guba ◽

Axel Kleespies ◽

Karl-Walter Jauch ◽

Christiane J. Bruns

Keyword(s):

Tumor Growth ◽

Solid Tumor ◽

Primary Tumor ◽

Primary Tumor Growth

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Defibrotide (DF) Targets Tumor-Microenvironmental Interactions and Sensitizes Multiple Myeloma and Solid Tumor Cells to Cytotoxic Chemotherapeutics.

Blood ◽

10.1182/blood.v104.11.286.286 ◽

2004 ◽

Vol 104 (11) ◽

pp. 286-286 ◽

Cited By ~ 4

Author(s):

Constantine S. Mitsiades ◽

Cecile Rouleau ◽

Krishna Menon ◽

Beverly Teicher ◽

Massimo Iacobelli ◽

...

Keyword(s):

Stem Cell ◽

Tumor Cell ◽

Tumor Cells ◽

Cell Lines ◽

Solid Tumor ◽

Single Agent ◽

Conventional Chemotherapy ◽

Adhesive Properties

Abstract Introduction: Defibrotide (DF) is a polydisperse oligonucleotide with anti-thrombotic, thrombolytic, anti-ischemic, and anti-adhesive properties, which selectively targets the microvasculature and has minimal hemorrhagic risk. DF is an effective treatment for veno-occlusive disease (VOD), an important regimen-related toxicity in stem cell transplantation characterized by endothelial cell injury. DF also augments stem cell mobilization by modulating adhesion in vivo. Because of its cytoprotective effect on the endothelium, we specifically investigated whether DF protects tumor cells from cytotoxic anti-tumor agents. Further, because of its broad anti-adhesive properties, we evaluated whether DF modulates the interaction of MM cells with bone marrow stromal cells (BMSCs), which confers growth, survival and drug resistance in the BM milieu. Methods: In vitro studies in isogenic dexamethasone (Dex)-sensitive and resistant MM cell lines (MM-1S and MM1R, respectively) showed that DF does not attenuate the sensitivity of MM cells to Dex, the proteasome inhibitor bortezomib (PS-341), melphalan (MEL), vinca alkaloids (vincristine, vinblastine), taxanes (paclitaxel) or platinum (cisplatin), but does decrease their sensitivity to doxorubicin. These selective effects in vitro of DF in protecting tumor cells against doxorubicin and modestly sensitizing MM cells to platinum was also confirmed in solid tumor breast (MCF-7) and colon (HT-29) carcinoma cell lines. Although DF had minimal in vitro inhibitory effect on MM or solid tumor cell growth in vitro, it showed in vivo activity as a single agent and enhanced the responsiveness of MM tumors to cytotoxic chemotherapeutics, such as MEL or cyclophosphamide, in human MM xenografts in SCID/NOD mice. The in vivo single-agent activity and chemosensitizing properties of DF, coupled with its lack of major in vitro activity, suggested that DF may not directly target tumor cells, but rather modulate tumor cell interaction with BMSCs. In an ex vivo model of co-culture of primary MM tumor cells with BMSCs (which protects MM cells against conventional chemotherapy), DF alone had a only modest effect on tumor cell viability, but it significantly enhanced MM cell sensitivity to cytotoxic chemotherapy (e.g. MEL), suggesting that a major component of the biological effects of DF may be attributable not to direct targeting of tumor cells, but to modulation of the interactions that tumor cells develop with the local stromal milieu. Conclusion: Our studies show that DF mediates in vivo anti-MM activity by abrogating interactions of MM cells with their BM milieu, thereby enhancing sensitivity and overcoming resistance to conventional chemotherapy. These data support future clinical trials of DF, in combination with both conventional and novel therapies, to improve patient outcome in MM.

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Tumor Cell Thrombin/PAR-1 Signaling Drives Pancreatic Ductal Adenocarcinoma Growth and Dissemination

Blood ◽

10.1182/blood.v126.23.1070.1070 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1070-1070

Author(s):

Matthew J. Flick ◽

Cheryl Rewerts ◽

Carolina Cruz ◽

Joseph S. Palumbo ◽

James P. Luyendyk ◽

...

Keyword(s):

Pancreatic Cancer ◽

Tumor Growth ◽

Tumor Cell ◽

Tumor Cells ◽

Coagulation System ◽

Ductal Adenocarcinoma ◽

Parental Line ◽

Experimental Metastasis ◽

Primary Tumor Growth ◽

Wild Type

Abstract Pancreatic ductal adenocarcinoma (PDAC) accounts for ~85% of diagnosed pancreatic cancers and is among the most lethal malignancies. The 5-year survival rate for pancreatic cancer patients has improved only marginally in the last 40 years (3% → 7%), with effectively no change in survival profile for patients with metastatic disease (2%). High mortality is linked to the aggressive and invasive nature of the malignancy and poor efficacy of limited treatment options, which collectively highlight the need for novel treatment strategies. Notably, analyses of pancreatic cancer in patients and animal models have demonstrated that PDAC is associated with robust coagulation system activity. Previous work has shown that patient PDAC tumor cells often express high levels of tissue factor (TF) and protease-activated receptor (PAR)-1. To determine the potential contribution of tumor cell derived-TF and PAR-1 to PDAC growth and metastasis, a novel tumor cell line (termed KPC2) was derived from mice in which PDAC tumorigenesis was induced by activation of two established pancreatic cancer alleles, KrasG12D and Trp53R172H. In transplant studies, tumor growth and experimental metastasis were evaluated using KPC2 cells in which TF or PAR-1 expression was suppressed by shRNA knockdown. In addition, the interplay of tumor-derived TF and PAR-1 with host factors in promoting tumor growth and experimental metastasis were evaluated in mice with genetically imposed deficits in coagulation system components. TF knockdown (to ~10% of the parental line) in KPC2 cells resulted in a significant diminution of both primary tumor growth and experimental metastasis. This reduction appeared to be linked to thrombin activity as primary tumor growth and experimental metastasis of parental KPC2 cells were significantly reduced in fIIlow mice (which constitutively express 10% of normal prothrombin) relative to wild-type mice. PAR-1 knockout mice displayed similar KPC2 growth and experimental metastasis to wild-type animals indicating that stromal cell-derived PAR-1 was not significant determinant. In stark contrast, shRNA-mediated knockdown of PAR-1 in KPC2 (to ~10% of the parental line) cells resulted in significantly diminished tumor growth and experimental metastasis. Diminished tumor growth was linked to reduced expression of the macrophage chemokine MCP-1 and the metalloproteinase MMP9 by the tumor cells as well as reduced thrombin-stimulated ERK phosphorylation. Our results suggest that a major mechanism of PDAC growth and dissemination is through TF/thrombin-driven PAR-1 signaling on tumor cells. Disclosures No relevant conflicts of interest to declare.

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