IU Indianapolis ScholarWorks :: Browsing by Author "Chen, Andy"

Browsing by Author "Chen, Andy"

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Attraction and Compaction of Migratory Breast Cancer Cells by Bone Matrix Proteins through Tumor-Osteocyte Interactions
(Nature Publishing Group, 2018-04-03) Chen, Andy; Wang, Luqi; Liu, Shengzhi; Wang, Yue; Liu, Yunlong; Wang, Mu; Nakshatri, Harikrishna; Li, Bai-Yan; Yokota, Hiroki; Biomedical Engineering, School of Engineering and Technology
Bone is a frequent site of metastasis from breast cancer. To understand the potential role of osteocytes in bone metastasis, we investigated tumor-osteocyte interactions using two cell lines derived from the MDA-MB-231 breast cancer cells, primary breast cancer cells, and MLO-A5/MLO-Y4 osteocyte cells. When three-dimensional (3D) tumor spheroids were grown with osteocyte spheroids, tumor spheroids fused with osteocyte spheroids and shrank. This size reduction was also observed when tumor spheroids were exposed to conditioned medium isolated from osteocyte cells. Mass spectrometry-based analysis predicted that several bone matrix proteins (e.g., collagen, biglycan) in conditioned medium could be responsible for tumor shrinkage. The osteocyte-driven shrinkage was mimicked by type I collagen, the most abundant organic component in bone, but not by hydroxyapatite, a major inorganic component in bone. RNA and protein expression analysis revealed that tumor-osteocyte interactions downregulated Snail, a transcription factor involved in epithelial-to-mesenchymal transition (EMT). An agarose bead assay showed that bone matrix proteins act as a tumor attractant. Collectively, the study herein demonstrates that osteocytes attract and compact migratory breast cancer cells through bone matrix proteins, suppress tumor migration, by Snail downregulation, and promote subsequent metastatic colonization.
Author Correction: Inhibitory effects of dopamine receptor D1 agonist on mammary tumor and bone metastasis
(Springer Nature, 2022-11-03) Minami, Kazumasa; Liu, Shengzhi; Liu, Yang; Chen, Andy; Wan, Qiaoqiao; Na, Sungsoo; Li, Bai‑Yan; Matsuura, Nariaki; Koizumi, Masahiko; Yin, Yukun; Gan, Liangying; Xu, Aihua; Li, Jiliang; Nakshatri, Harikrishna; Yokota, Hiroki; Biomedical Engineering, School of Engineering and Technology
This corrects the article "Inhibitory Effects of Dopamine Receptor D1 Agonist on Mammary Tumor and Bone Metastasis" in volume 7, 45686. doi: 10.1038/srep45686
Effects of a checkpoint kinase inhibitor, AZD7762, on tumor suppression and bone remodeling
(Spandidos Publications, 2018-09) Wang, Luqi; Wang, Yue; Chen, Andy; Jalali, Aydin; Liu, Shengzhi; Guo, Yunxia; Na, Sungsoo; Nakshatri, Harikrishna; Li, Bai-Yan; Yokota, Hiroki; Biomedical Engineering, School of Engineering and Technology
Chemotherapy for suppressing tumor growth and metastasis tends to induce various effects on other organs. Using AZD7762, an inhibitor of checkpoint kinase (Chk) 1 and 2, the present study examined its effect on mammary tumor cells in addition to bone cells (osteoclasts, osteoblasts and osteocytes), using monolayer cell cultures and three-dimensional (3D) cell spheroids. The results revealed that AZD7762 blocked the proliferation of 4T1.2 mammary tumor cells and suppressed the development of RAW264.7 pre-osteoclast cells by downregulating nuclear factor of activated T cells cytoplasmic 1. AZD7762 also promoted the mineralization of MC3T3 osteoblast-like cells and 3D bio-printed bone constructs of MLO-A5 osteocyte spheroids. While a Chk1 inhibitor, PD407824, suppressed the proliferation of tumor cells and the differentiation of pre-osteoclasts, its effect on gene expression in osteoblasts was markedly different compared with AZD7762. Western blotting indicated that the stimulating effect of AZD7762 on osteoblast development was associated with the inhibition of Chk2 and the downregulation of cellular tumor antigen p53. The results of the present study indicated that in addition to acting as a tumor suppressor, AZD7762 may prevent bone loss by inhibiting osteoclastogenesis and stimulating osteoblast mineralization.
Enhancement of osteoblastogenesis and suppression of osteoclastogenesis by inhibition of de-phosphorylation of eukaryotic translation initiation factor 2 alpha
(Smart Science and Technology, LLC, 2015) Hamamura, Kazunori; Chen, Andy; Yokota, Hiroki; Department of Anatomy and Cell Biology, IU School of Medicine
The phosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2α) is activated in response to various stresses such as viral infection, nutrient deprivation, and stress to the endoplasmic reticulum. Severe stress to the endoplasmic reticulum, for instance, induces an apoptotic pathway, while mild stress, on the contrary, leads to a pro-survival pathway. Little has been known about the elaborate role of eIF2α phosphorylation in the development of bone-forming osteoblasts and bone-resorbing osteoclasts. Using salubrinal and guanabenz as inhibitors of the de-phosphorylation of eIF2α, we have recently reported that the phosphorylation of eIF2α significantly alters fates of both osteoblasts and osteoclasts. Based on our recent findings, we review in this research highlight the potential mechanisms of the enhancement of osteoblastogenesis and the suppression of osteoclastogenesis through the elevated level of phosphorylated eIF2α.
Enhancing anti-tumor potential: low-intensity vibration suppresses osteosarcoma progression and augments MSCs' tumor-suppressive abilities
(Ivyspring, 2024-01-27) Xiong, Xue; Huo, Qingji; Li, Kexin; Cui, Changpeng; Chang, Chunyi; Park, Charles; Ku, BonHeon; Hong, Chin-Suk; Lim, HeeChang; Pandya, Pankita H.; Saadatzadeh, M. Reza; Bijangi-Vishehsaraei, Khadijeh; Lin, Chien-Chi; Kacena, Melissa A.; Pollok, Karen E.; Chen, Andy; Liu, Jing; Thompson, William R.; Li, Xue-Lian; Li, Bai-Yan; Yokota, Hiroki; Anatomy, Cell Biology and Physiology, School of Medicine
Rationale: Osteosarcoma (OS), a common malignant bone tumor, calls for the investigation of novel treatment strategies. Low-intensity vibration (LIV) presents itself as a promising option, given its potential to enhance bone health and decrease cancer susceptibility. This research delves into the effects of LIV on OS cells and mesenchymal stem cells (MSCs), with a primary focus on generating induced tumor-suppressing cells (iTSCs) and tumor-suppressive conditioned medium (CM). Methods: To ascertain the influence of vibration frequency, we employed numerical simulations and conducted experiments to determine the most effective LIV conditions. Subsequently, we generated iTSCs and CM through LIV exposure and assessed the impact of CM on OS cells. We also explored the underlying mechanisms of the tumor-suppressive effects of LIV-treated MSC CM, with a specific focus on vinculin (VCL). We employed cytokine array, RNA sequencing, and Western blot techniques to investigate alterations in cytokine profiles, transcriptomes, and tumor suppressor proteins. Results: Numerical simulations validated LIV frequencies within the 10-100 Hz range. LIV induced notable morphological changes in OS cells and MSCs, confirming its dual role in inhibiting OS cell progression and promoting MSC conversion into iTSCs. Upregulated VCL expression enhanced MSC responsiveness to LIV, significantly bolstering CM's efficacy. Notably, we identified tumor suppressor proteins in LIV-treated CM, including procollagen C endopeptidase enhancer (PCOLCE), histone H4 (H4), peptidylprolyl isomerase B (PPIB), and aldolase A (ALDOA). Consistently, cytokine levels decreased significantly in LIV-treated mouse femurs, and oncogenic transcript levels were downregulated in LIV-treated OS cells. Moreover, our study demonstrated that combining LIV-treated MSC CM with chemotherapy drugs yielded additive anti-tumor effects. Conclusions: LIV effectively impeded the progression of OS cells and facilitated the transformation of MSCs into iTSCs. Notably, iTSC-derived CM demonstrated robust anti-tumor properties and the augmentation of MSC responsiveness to LIV via VCL. Furthermore, the enrichment of tumor suppressor proteins within LIV-treated MSC CM and the reduction of cytokines within LIV-treated isolated bone underscore the pivotal tumor-suppressive role of LIV within the bone tumor microenvironment.
Finite Element Analysis of the Mouse Distal Femur with Tumor Burden in Response to Knee Loading
(Medip Academy, 2018) Jiang, Feifei; Liu, Shengzhi; Chen, Andy; Li, Bai-Yan; Robling, Alexander G.; Chen, Jie; Yokota, Hiroki; Mechanical and Energy Engineering, School of Engineering and Technology
Breast cancer-associated bone metastasis induces bone loss, followed by an increased risk of bone fracture. To develop a strategy for preventing tumor growth and protecting bone, an understanding of the mechanical properties of bone under tumor burden is indispensable. Using a mouse model of mammary tumor, we conducted finite element analysis (FEA) of two bone samples from the distal femur. One sample was from a placebo-treated mouse, and the other was from a mouse treated with the investigational drug candidate, PD407824, an inhibitor of checkpoint kinases. Mechanical testing and microCT images revealed that bone strength is improved by administration of PD407824. In response to loading to the knee, FEA predicted that the peaks of von Mises stress, an indicator of fracture yielding, as well as the third principal compressive stress, were higher in the placebo-treated femur than the drug-treated femur. Higher peak stresses in trabecular segments were observed in the lateral condyle, a critical region for integrity of the knee joint. Collectively, this FE study supports the notion that mechanical weakening of the femur was observed in the tumor-invaded trabecular bone, and chemical agents such as PD407824 may potentially assist in preventing bone loss and bone fracture.
Finite Element Analysis of the Mouse Proximal Ulna in Response to Elbow Loading
(Springer, 2018) Jiang, Feifei; Jalali, Aydin; Deguchi, Chie; Chen, Andy; Liu, Shengzhi; Kondo, Rika; Minami, Kazumasa; Horiuchi, Takashi; Li, Bai-Yan; Robling, Alexander G.; Chen, Jie; Yokota, Hiroki; Mechanical and Energy Engineering, School of Engineering and Technology
Bone is a mechano-sensitive tissue that alters its structure and properties in response to mechanical loading. We have previously shown that application of lateral dynamic loads to a synovial joint, such as the knee and elbow, suppresses degradation of cartilage and prevents bone loss in arthritis and postmenopausal mouse models, respectively. While loading effects on pathophysiology have been reported, mechanical effects on the loaded joint are not fully understood. Because the direction of joint loading is non-axial, not commonly observed in daily activities, strain distributions in the laterally loaded joint are of great interest. Using elbow loading, we herein characterized mechanical responses in the loaded ulna focusing on the distribution of compressive strain. In response to 1-N peak-to-peak loads, which elevate bone mineral density and bone volume in the proximal ulna in vivo, we conducted finite-element analysis and evaluated strain magnitude in three loading conditions. The results revealed that strain of ~ 1000 μstrain (equivalent to 0.1% compression) or above was observed in the limited region near the loading site, indicating that the minimum effective strain for bone formation is smaller with elbow loading than axial loading. Calcein staining indicated that elbow loading increased bone formation in the regions predicted to undergo higher strain.
Guanabenz Downregulates Inflammatory Responses via eIF2α Dependent and Independent Signaling
(MDPI, 2016-05) Takigawa, Shinya; Chen, Andy; Nishimura, Akinobu; Liu, Shengzhi; Li, Bai-Yan; Sudo, Akihiro; Yokota, Hiroki; Hamamura, Kazunori; Department of Biomedical Engineering, School of Engineering and Technology
Integrated stress responses (ISR) may lead to cell death and tissue degeneration via eukaryotic translation initiation factor 2 α (eIF2α)-mediated signaling. Alleviating ISR by modulating eIF2α phosphorylation can reduce the symptoms associated with various diseases. Guanabenz is known to elevate the phosphorylation level of eIF2α and reduce pro-inflammatory responses. However, the mechanism of its action is not well understood. In this study, we investigated the signaling pathway through which guanabenz induces anti-inflammatory effects in immune cells, in particular macrophages. Genome-wide mRNA profiling followed by principal component analysis predicted that colony stimulating factor 2 (Csf2, or GM-CSF as granulocyte macrophage colony stimulating factor) is involved in the responses to guanabenz. A partial silencing of Csf2 or eIF2α by RNA interference revealed that Interleukin-6 (IL6), Csf2, and Cyclooxygenase-2 (Cox2) are downregulated by guanabenz-driven phosphorylation of eIF2α. Although expression of IL1β and Tumor Necrosis Factor-α (TNFα) was suppressed by guanabenz, their downregulation was not directly mediated by eIF2α signaling. Collectively, the result herein indicates that anti-inflammatory effects by guanabenz are mediated by not only eIF2α-dependent but also eIF2α-independent signaling.
Inhibiting checkpoint kinase 1 protects bone from bone resorption by mammary tumor in a mouse model
(Impact Journals, 2018-01-19) Liu, Shengzhi; Liu, Yang; Minami, Kazumasa; Chen, Andy; Wan, Qiaoqiao; Yin, Yukun; Gan, Liangying; Xu, Aihua; Matsuura, Nariaki; Koizumi, Masahiko; Liu, Yunlong; Na, Sungsoo; Li, Jiliang; Nakshatri, Harikrishna; Li, Bai-Yan; Yokota, Hiroki; Biomedical Engineering, School of Engineering and Technology
DNA damage response plays a critical role in tumor growth, but little is known about its potential role in bone metabolism. We employed selective inhibitors of Chk1 and examined their effects on the proliferation and migration of mammary tumor cells as well as the development of osteoblasts and osteoclasts. Further, using a mouse model of bone metastasis we evaluated the effects of Chk1 inhibitors on bone quality. Chk1 inhibitors blocked the proliferation, survival, and migration of tumor cells in vitro and suppressed the development of bone-resorbing osteoclasts by downregulating NFATc1. In the mouse model, Chk1 inhibitor reduced osteolytic lesions and prevented mechanical weakening of the femur and tibia. Analysis of RNA-seq expression data indicated that the observed effects were mediated through the regulation of eukaryotic translation initiation factor 2 alpha, stress to the endoplasmic reticulum, S100 proteins, and bone remodeling-linked genes. Our findings suggest that targeting Chk1 signaling without adding DNA damaging agents may protect bone from degradation while suppressing tumor growth and migration.
Inhibitory Effects of Dopamine Receptor D1 Agonist on Mammary Tumor and Bone Metastasis
(Springer NPG, 2017-03-04) Minami, Kazumasa; Liu, Shengzhi; Liu, Yang; Chen, Andy; Wan, Qiaoqiao; Na, Sungsoo; Li, Bai-Yan; Matsuura, Nariaki; Koizumi, Masahiko; Yin, Yukun; Gan, Liangying; Xu, Aihua; Li, Jiliang; Nakshatri, Harikrishna; Yokota, Hiroki; Biomedical Engineering, School of Engineering and Technology
Dopaminergic signaling plays a critical role in the nervous system, but little is known about its potential role in breast cancer and bone metabolism. A screening of ~1,000 biologically active compounds revealed that a selective agonist of dopamine receptor D1 (DRD1), A77636, inhibited proliferation of 4T1.2 mammary tumor cells as well as MDA-MB-231 breast cancer cells. Herein, we examined the effect of A77636 on bone quality using a mouse model of bone metastasis from mammary tumor. A77636 inhibited migration of cancer cells in a DRD1-dependent fashion and suppressed development of bone-resorbing osteoclasts by downregulating NFATc1 through the elevation of phosphorylation of eIF2α. In the mouse model of bone metastasis, A77636 reduced osteolytic lesions and prevented mechanical weakening of the femur and tibia. Collectively, we expect that dopaminergic signaling might provide a novel therapeutic target for breast cancer and bone metastasis.

Browsing by Author "Chen, Andy"

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