Chun Lung Chiu

All Publications

• The olfactory receptor OR51E2 regulates prostate cancer aggressiveness and modulates STAT3 in prostate cancer cells and in xenograft tumors. BMC cancer Thomsen, M. T., Busk, M., Zhang, D., Chiu, C. L., Zhao, H., Garcia-Marques, F. J., Bermudez, A., Pitteri, S., Borre, M., Brooks, J. D., Nyengaard, J. R. 2025; 25 (1): 535

  Abstract

  Despite advancements in the detection and treatment of prostate cancer, the molecular mechanisms underlying its progression remain unclear. This study aimed to investigate the role of the receptor OR51E2, which is commonly upregulated in prostate cancer, in the progression of this disease.We investigated the physiological effects of OR51E2 through CRISPR-Cas9-induced monoclonal OR51E2 knockout. We assessed in vitro and in vivo tumorigenicity and conducted transcriptomic and proteomic analyses of xenograft tumors derived from these knockout cells. Furthermore, we analyzed the effects of differences in OR51E2-expression levels in patients from a TCGA cohort.OR51E2-knockout cells exhibited increased proliferation, migration, adhesion, anchorage-independent colony formation, and tumor growth rates, resulting in a more aggressive cancer phenotype. Omics analyses revealed several potential pathways associated with significant molecular changes, notably an aberration in the STAT3 pathway linked to IL-6 signaling, highlighting a connection to inflammatory pathways. TCGA cohort analysis revealed that prostate cancer patients with low tumor OR51E2 expression had a worse prognosis and a higher average Gleason grade than those with higher expression levels. Additionally, this analysis supported the putative OR51E2-related modulation of the STAT3 pathway.OR51E2 is regulated throughout prostate cancer progression and actively influences cancer cell physiology affecting cancer aggressiveness. Reduced OR51E2 expression may adversely affect patient outcomes, potentially through alterations in the STAT3 pathway that impact cellular responses to inflammatory signaling.

  View details for DOI 10.1186/s12885-025-13928-0

  View details for PubMedID 40128715

  View details for PubMedCentralID 3566163

• Targeting AXL inhibits the growth and metastasis of prostate cancer in bone. Clinical cancer research : an official journal of the American Association for Cancer Research Chiu, C. L., Zhang, D., Zhao, H., Wei, Y., Polasko, A. L., Thomsen, M. T., Yang, V., Yang, K. K., Hauck, S., Peterson, E. E., Wen, R. M., Qiu, Z., Corey, E., Miao, Y. R., Rankin, E. B., Peehl, D. M., Huang, J., Giaccia, A. J., Brooks, J. D. 2025

  Abstract

  After failing primary and secondary hormonal therapy, castration-resistant and neuroendocrine prostate cancer metastatic to the bone is invariably lethal, although treatment with docetaxel and carboplatin can modestly improve survival. Therefore, agents targeting biologically relevant pathways in PCa and potentially synergizing with docetaxel and carboplatin in inhibiting bone metastasis growth are urgently needed.Phosphorylated (activated) AXL expression in human prostate cancer bone metastases was assessed by immunohistochemical staining. We evaluated the effects of a novel soluble AXL signaling inhibitor, sAXL (batiraxcept or AVB-S6-500), on the tumor growth and lung metastases in PCa patient-derived xenograft models (PDX) that implanted intratibally. After injection of LuCaP cells into the tibiae, tumors were treated with batiraxcept and docetaxel or carboplatin alone or in combination, and tumor growth was monitored by serum PSA or bioluminescence. Tumor burden was quantified by human-specific Ku70 staining, and metastasis to the lung was determined using qPCR. Transcriptomic profiling, western blotting and immunohistochemistry were performed to identify treatment-regulated gene and protein profile changes.High AXL phosphorylation in human PCa bone metastases correlated with shortened survival. Batiraxcept alone or in combination with docetaxel or carboplatin significantly suppressed intratibial tumor growth and suppressed metastasis to the lung through multiple mechanisms, including repression of cancer stemness genes (CD44, ALDH1A1, TACSTD2, ATXN1) and the PI3K, JAK, MAPK, and E2F1/NUSAP1 signaling pathways.Our study provides a robust preclinical rationale and mechanisms of action for using batiraxcept as a single agent or in combination with docetaxel or carboplatin to treat lethal mPCa.

  View details for DOI 10.1158/1078-0432.CCR-24-3028

  View details for PubMedID 39879384

• Inhibition of MARCKS phosphorylation attenuates of dendritic cell migration in a murine model of acute asthma. European journal of pharmacology Lee, C. C., Chen, C. H., Kenyon, N. J., Wang, C. N., Tsai, H. C., Chiu, C. L., Chen, Y., Forteza, R. M., Wu, R. 2024; 980: 176867

  Abstract

  MARCKS (myristoylated alanine-rich C kinase substrates) serves as a substrate for protein kinase C, residing in the plasma membrane while acts as an actin filament crosslinking protein. This investigation aims to elucidate phosphorylated MARCKS (p-MARCKS) levels and activity in allergic asthma patients and explore the therapeutic potential of peptide inhibitors targeting p-MARCKS in an acute mouse model of allergic asthma.Immunohistochemistry and histology staining were employed on lung tissue slides to evaluate p-MARCKS expression and allergic asthma symptoms. Airway resistance was measured using invasive whole-body plethysmography. Flow cytometry detected lung dendritic cell migration, and migration/maturation assays were conducted on isolated murine bone marrow-derived dendritic cells (BM-DCs).Elevated p-MARCKS expression was observed in both human asthmatic tissues and animal models immunized with ovalbumin or Alternaria alternata. Remarkably, asthmatic individuals showed elevated high p-MARCKS expression in lung tissues. Intraperitoneal injection of the peptide MPS, targeting the MARCKS phosphorylation site domain, before allergen challenged, effectively suppressed MARCKS phosphorylation in murine lung tissues. MPS inhibited both in vivo and in vitro migration and maturation of dendritic cells (BM-DCs) and reduced Th2-related lymphocyte activation in bronchoalveolar lavage fluid (BALF). MPS pretreatment additionally suppressed all symptoms associated with allergic airway asthma, including a reduction in inflammatory cell influx, airway mucous cell metaplasia, and airway hyperreactivity.These findings suggest that phosphorylated MARCKS occurs in asthmatic lung tissue, and the inhibition of MARCKS phosphorylation by the MPS peptide reduces dendritic cell migration and Th2-related lymphocytes in the lungs in a murine model of acute asthma.

  View details for DOI 10.1016/j.ejphar.2024.176867

  View details for PubMedID 39111683

• Establishing and characterizing the molecular profiles, cellular features, and clinical utility of a patient-derived xenograft model using benign prostatic tissues. Laboratory investigation; a journal of technical methods and pathology Polasko, A. L., Zhang, D., Ramraj, A., Chiu, C. L., Garcia-Marques, F. J., Bermudez, A., Kapp, K., Peterson, E., Qiu, Z., Pollack, A. S., Zhao, H., Pollack, J. R., Pitteri, S. J., Brooks, J. D. 2024: 102129

  Abstract

  Benign Prostatic Hyperplasia (BPH) is a common condition marked by the enlargement of the prostate gland, which often leads to significant urinary symptoms and a decreased quality of life. The development of clinically relevant animal models is crucial for understanding the pathophysiology of BPH and improving treatment options. This study aims to establish a patient-derived xenograft (PDX) model using benign prostatic tissues to explore the molecular and cellular mechanisms of BPH. PDXs were generated by implanting fresh BPH (transition zone) and paired normal (peripheral zone) prostate tissue from eight patients under the renal capsule of immunodeficient male mice. Tissue weight, architecture, cellular proliferation, apoptosis, prostate-specific marker expression, and molecular profiles of PDXs were assessed after 1 week, 1 month, 2 months, or 3 months of implantation by immunohistochemistry, ELISA, transcriptomics, and proteomics. Responses to finasteride, a standard-of-care therapy, were evaluated. PDXs maintained the histological and molecular characteristics of the parental human tissues. BPH, but not normal PDXs, demonstrated significant increases in weight and cellular proliferation, particularly at 1 month. Molecular profiling revealed specific gene and protein expression patterns correlating with BPH pathophysiology. Specifically, an increased immune and stress response was observed at 1 week, followed by increased expression of proliferation markers and BPH-specific stromal signaling molecules, such as BMP5 and CXCL13, at 1 month. Graft stabilization to pre-implant characteristics was apparent between 2 and 3 months. Treatment with finasteride reduced proliferation, increased apoptosis, and induced morphological changes consistent with therapeutic responses observed in human BPH. Our PDX model recapitulates the morphological, histological, and molecular features of human BPH, offering a significant advancement in modeling the complex interactions of cell types in BPH microenvironments. These PDXs respond to therapeutic intervention as expected, providing a valuable tool for preclinical testing of new therapeutics which will improve the well-being for BPH patients.

  View details for DOI 10.1016/j.labinv.2024.102129

  View details for PubMedID 39222914

• AZGP1 deficiency promotes angiogenesis in prostate cancer. Journal of translational medicine Wen, R. M., Qiu, Z., Marti, G. E., Peterson, E. E., Marques, F. J., Bermudez, A., Wei, Y., Nolley, R., Lam, N., Polasko, A. L., Chiu, C. L., Zhang, D., Cho, S., Karageorgos, G. M., McDonough, E., Chadwick, C., Ginty, F., Jung, K. J., Machiraju, R., Mallick, P., Crowley, L., Pollack, J. R., Zhao, H., Pitteri, S. J., Brooks, J. D. 2024; 22 (1): 383

  Abstract

  Loss of AZGP1 expression is a biomarker associated with progression to castration resistance, development of metastasis, and poor disease-specific survival in prostate cancer. However, high expression of AZGP1 cells in prostate cancer has been reported to increase proliferation and invasion. The exact role of AZGP1 in prostate cancer progression remains elusive.AZGP1 knockout and overexpressing prostate cancer cells were generated using a lentiviral system. The effects of AZGP1 under- or over-expression in prostate cancer cells were evaluated by in vitro cell proliferation, migration, and invasion assays. Heterozygous AZGP1± mice were obtained from European Mouse Mutant Archive (EMMA), and prostate tissues from homozygous knockout male mice were collected at 2, 6 and 10 months for histological analysis. In vivo xenografts generated from AZGP1 under- or over-expressing prostate cancer cells were used to determine the role of AZGP1 in prostate cancer tumor growth, and subsequent proteomics analysis was conducted to elucidate the mechanisms of AZGP1 action in prostate cancer progression. AZGP1 expression and microvessel density were measured in human prostate cancer samples on a tissue microarray of 215 independent patient samples.Neither the knockout nor overexpression of AZGP1 exhibited significant effects on prostate cancer cell proliferation, clonal growth, migration, or invasion in vitro. The prostates of AZGP1-/- mice initially appeared to have grossly normal morphology; however, we observed fibrosis in the periglandular stroma and higher blood vessel density in the mouse prostate by 6 months. In PC3 and DU145 mouse xenografts, over-expression of AZGP1 did not affect tumor growth. Instead, these tumors displayed decreased microvessel density compared to xenografts derived from PC3 and DU145 control cells, suggesting that AZGP1 functions to inhibit angiogenesis in prostate cancer. Proteomics profiling further indicated that, compared to control xenografts, AZGP1 overexpressing PC3 xenografts are enriched with angiogenesis pathway proteins, including YWHAZ, EPHA2, SERPINE1, and PDCD6, MMP9, GPX1, HSPB1, COL18A1, RNH1, and ANXA1. In vitro functional studies show that AZGP1 inhibits human umbilical vein endothelial cell proliferation, migration, tubular formation and branching. Additionally, tumor microarray analysis shows that AZGP1 expression is negatively correlated with blood vessel density in human prostate cancer tissues.AZGP1 is a negative regulator of angiogenesis, such that loss of AZGP1 promotes angiogenesis in prostate cancer. AZGP1 likely exerts heterotypical effects on cells in the tumor microenvironment, such as stromal and endothelial cells. This study sheds light on the anti-angiogenic characteristics of AZGP1 in the prostate and provides a rationale to target AZGP1 to inhibit prostate cancer progression.

  View details for DOI 10.1186/s12967-024-05183-x

  View details for PubMedID 38659028

  View details for PubMedCentralID 321763

• C-terminal tensin-like (CTEN) knockin alleviates cystic kidney defects in Tensin-1 knockout mice. Genes & diseases Chiu, C. L., Hong, S. Y., Tan, Y., Lee, Y. J., Shih, Y. P., Tepper, C. G., Lo, S. H. 2023; 10 (3): 643-646

  View details for DOI 10.1016/j.gendis.2022.05.035

  View details for PubMedID 37396551

  View details for PubMedCentralID PMC10308109

• NUSAP1 Binds ILF2 to Modulate R-Loop Accumulation and DNA Damage in Prostate Cancer. International journal of molecular sciences Chiu, C. L., Li, C. G., Verschueren, E., Wen, R. M., Zhang, D., Gordon, C. A., Zhao, H., Giaccia, A. J., Brooks, J. D. 2023; 24 (7)

  Abstract

  Increased expression of NUSAP1 has been identified as a robust prognostic biomarker in prostate cancer and other malignancies. We have previously shown that NUSAP1 is positively regulated by E2F1 and promotes cancer invasion and metastasis. To further understand the biological function of NUSAP1, we used affinity purification and mass spectrometry proteomic analysis to identify NUSAP1 interactors. We identified 85 unique proteins in the NUSAP1 interactome, including ILF2, DHX9, and other RNA-binding proteins. Using proteomic approaches, we uncovered a function for NUSAP1 in maintaining R-loops and in DNA damage response through its interaction with ILF2. Co-immunoprecipitation and colocalization using confocal microscopy verified the interactions of NUSAP1 with ILF2 and DHX9, and RNA/DNA hybrids. We showed that the microtubule and charged helical domains of NUSAP1 were necessary for the protein-protein interactions. Depletion of ILF2 alone further increased camptothecin-induced R-loop accumulation and DNA damage, and NUSAP1 depletion abolished this effect. In human prostate adenocarcinoma, NUSAP1 and ILF2 mRNA expression levels are positively correlated, elevated, and associated with poor clinical outcomes. Our study identifies a novel role for NUSAP1 in regulating R-loop formation and accumulation in response to DNA damage through its interactions with ILF2 and hence provides a potential therapeutic target.

  View details for DOI 10.3390/ijms24076258

  View details for PubMedID 37047232

• The Role of MARCKS in Metastasis and Treatment Resistance of Solid Tumors. Cancers Chiu, C. L., Zhao, H., Chen, C. H., Wu, R., Brooks, J. D. 2022; 14 (19)

  Abstract

  The myristoylated alanine-rich C-kinase substrate (MARCKS) is a membrane-associated protein kinase C (PKC) substrate ubiquitously expressed in eukaryotic cells. MARCKS plays important roles in multiple cellular processes, including cell adhesion and motility, mucin secretion, exocytosis, and inflammatory response. Aberrant MARCKS signaling has been observed in the development and progression of multiple cancer types. In addition, MARCKS facilitates cancer metastasis through modulating cancer cell migration and invasion. Moreover, MARCKS contributes to treatment resistance, likely by promoting cancer stem cell renewal as well as immunosuppression. In this review, we describe MARCKS protein structure, cellular localization, and biological functions. We then discuss the role of MARCKS in cancer metastasis as well as its mechanisms of action in solid tumors. Finally, we review recent advances in targeting MARCKS as a new therapeutic strategy in cancer management.

  View details for DOI 10.3390/cancers14194925

  View details for PubMedID 36230850

• Sialylated glycoproteins as biomarkers and drivers of progression in prostate cancer. Carbohydrate research Wen, R., Zhao, H., Zhang, D., Chiu, C., Brooks, J. D. 2022; 519: 108598

  Abstract

  Sialic acids have been implicated in cancer initiation, progression, and immune evasion in diverse human malignancies. Sialylation of terminal glycans on cell surface and secreted glycoproteins is a long-recognized feature of cancer cells. Recently, immune checkpoint inhibitor immunotherapy has tremendously improved the outcomes of patients with various cancers. However, available immunotherapy approaches have had limited efficacy in metastatic castration-resistant prostate cancer. Sialic acid modified glycoproteins in prostate cancers and their interaction with Siglec receptors on tumor infiltrating immune cells might underlie immunosuppressive signaling in prostate cancer. Here, we summarize the function of sialic acids and relevant glycosynthetic enzymes in cancer initiation and progression. We also discuss the possible uses of sialic acids as biomarkers in prostate cancer and the potential methods for targeting Siglec-sialic acid interactions for prostate cancer treatment.

  View details for DOI 10.1016/j.carres.2022.108598

  View details for PubMedID 35691122

• Hyperactivity of Mek in TNS1 knockouts leads to potential treatments for cystic kidney diseases. Cell death & disease Wu, Z. Y., Chiu, C. L., Lo, E., Lee, Y. J., Yamada, S., Lo, S. H. 2019; 10 (12): 871

  Abstract

  Cystic kidney disease is the progressive development of multiple fluid-filled cysts that may severely compromise kidney functions and lead to renal failure. TNS1 (tensin-1) knockout mice develop cystic kidneys and die from renal failure. Here, we have established TNS1-knockout MDCK cells and applied 3D culture system to investigate the mechanism leading to cyst formation. Unlike wild-type MDCK cells, which form cysts with a single lumen, TNS1-knockout cysts contain multiple lumens and upregulated Mek/Erk activities. The multiple lumen phenotype and Mek/Erk hyperactivities are rescued by re-expression of wild-type TNS1 but not the TNS1 mutant lacking a fragment essential for its cell-cell junction localization. Furthermore, Mek inhibitor treatments restore the multiple lumens back to single lumen cysts. Mek/Erk hyperactivities are also detected in TNS1-knockout mouse kidneys. Treatment with the Mek inhibitor trametinib significantly reduces the levels of interstitial infiltrates, fibrosis and dilated tubules in TNS1-knockout kidneys. These studies establish a critical role of subcellular localization of TNS1 in suppressing Mek/Erk signaling and maintaining lumenogenesis, and provide potential therapeutic strategies by targeting the Mek/Erk pathway for cystic kidney diseases.

  View details for DOI 10.1038/s41419-019-2119-7

  View details for PubMedID 31740667

  View details for PubMedCentralID PMC6861224

• Polygonum multiflorum Decreases Airway Allergic Symptoms in a Murine Model of Asthma. The American journal of Chinese medicine Lee, C. C., Lee, Y. L., Wang, C. N., Tsai, H. C., Chiu, C. L., Liu, L. F., Lin, H. Y., Wu, R. 2016; 44 (1): 133-47

  Abstract

  The root of Polygonum multiflorum (also called He-Shou-Wu in Chinese) is a common herb and medicinal food in Asia used for its anti-aging properties. Our study investigated the therapeutic potential of an extract of the root of Polygonum multiflorum (PME) in allergic asthma by using a mouse model. Feeding of 0.5 and 1 mg/mouse PME inhibited ovalbumin (OVA)-induced allergic asthma symptoms, including airway inflammation, mucus production, and airway hyper-responsiveness (AHR), in a dose-dependent manner. To discern PME's mechanism of action, we examined the profile and cytokine production of inflammatory cells in bronchial alveolar lavage fluid (BALF). We found that eosinophils, the main inflammatory cell infiltrate in the lung of OVA-immunized mice, significantly decreased after PME treatment. Th2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13, eotaxin, and the proinflammatory cytokine tumor necrosis factor (TNF)-[Formula: see text], decreased in PME-treated mice. Elevated mRNA expression of Th2 transcription factor GATA-3 in the lung tissue was also inhibited after oral feeding of PME in OVA-immunized mice. Thus, we conclude that PME produces anti-asthma activity through the inhibition of Th2 cell activation.

  View details for DOI 10.1142/S0192415X16500099

  View details for PubMedID 26916919

• Targeting myristoylated alanine-rich C kinase substrate phosphorylation site domain in lung cancer. Mechanisms and therapeutic implications. American journal of respiratory and critical care medicine Chen, C. H., Statt, S., Chiu, C. L., Thai, P., Arif, M., Adler, K. B., Wu, R. 2014; 190 (10): 1127-38

  Abstract

  Phosphorylation of myristoylated alanine-rich C kinase substrate (phospho-MARCKS) at the phosphorylation site domain (PSD) is crucial for mucus granule secretion and cell motility, but little is known concerning its function in lung cancer.We aimed to determine if MARCKS PSD activity can serve as a therapeutic target and to elucidate the molecular basis of this potential.The clinical relevance of phospho-MARCKS was first confirmed. Next, we used genetic approaches to verify the functionality and molecular mechanism of phospho-MARCKS. Finally, cancer cells were pharmacologically inhibited for MARCKS activity and subjected to functional bioassays.We demonstrated that higher phospho-MARCKS levels were correlated with shorter overall survival of lung cancer patients. Using shRNA silencing and ectopic expression of wild-type and PSD-mutated (S159/163A) MARCKS, we showed that elevated phospho-MARCKS promoted cancer growth and erlotinib resistance. Further studies demonstrated an interaction of phosphoinositide 3-kinase with MARCKS, but not with phospho-MARCKS. Interestingly, phospho-MARCKS acted in parallel with increased phosphatidylinositol (3,4,5)-triphosphate pools and AKT activation in cells. Through treatment with a 25-mer peptide targeting the MARCKS PSD motif (MPS peptide), we were able to suppress tumor growth and metastasis in vivo, and reduced levels of phospho-MARCKS, phosphatidylinositol (3,4,5)-triphosphate, and AKT activity. This peptide also enhanced the sensitivity of lung cancer cells to erlotinib treatment, especially those with sustained activation of phosphoinositide 3-kinase/AKT signaling.These results suggest a key role for MARCKS PSD in cancer disease and provide a unique strategy for inhibiting the activity of MARCKS PSD as a treatment for lung cancer.

  View details for DOI 10.1164/rccm.201408-1505OC

  View details for PubMedID 25318062

  View details for PubMedCentralID PMC4299640

• A novel predictor of cancer malignancy: up-regulation of myristoylated alanine-rich C kinase substrate phosphorylation in lung cancer. American journal of respiratory and critical care medicine Chen, C. H., Chiu, C. L., Adler, K. B., Wu, R. 2014; 189 (8): 1002-4

  View details for DOI 10.1164/rccm.201401-0053LE

  View details for PubMedID 24735036

  View details for PubMedCentralID PMC4098099