Browsing by Author "Lu, Xin"

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    Acoustofluidic assembly of primary tumor-derived organotypic cell clusters for rapid evaluation of cancer immunotherapy
    (BMC, 2023-02-04) Wu, Zhuhao; Ao, Zheng; Cai, Hongwei; Li, Xiang; Chen, Bin; Tu, Honglei; Wang, Yijie; Lu, Rongze Olivia; Gu, Mingxia; Cheng, Liang; Lu, Xin; Guo, Feng; Medicine, School of Medicine
    Cancer immunotherapy shows promising potential for treating breast cancer. While patients may have heterogeneous treatment responses for adjuvant therapy, it is challenging to predict an individual patient’s response to cancer immunotherapy. Here, we report primary tumor-derived organotypic cell clusters (POCCs) for rapid and reliable evaluation of cancer immunotherapy. By using a label-free, contactless, and highly biocompatible acoustofluidic method, hundreds of cell clusters could be assembled from patient primary breast tumor dissociation within 2 min. Through the incorporation of time-lapse living cell imaging, the POCCs could faithfully recapitulate the cancer-immune interaction dynamics as well as their response to checkpoint inhibitors. Superior to current tumor organoids that usually take more than two weeks to develop, the POCCs can be established and used for evaluation of cancer immunotherapy within 12 h. The POCCs can preserve the cell components from the primary tumor due to the short culture time. Moreover, the POCCs can be assembled with uniform fabricate size and cell composition and served as an open platform for manipulating cell composition and ratio under controlled treatment conditions with a short turnaround time. Thus, we provide a new method to identify potentially immunogenic breast tumors and test immunotherapy, promoting personalized cancer therapy.
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    CDHu40: a novel marker gene set of neuroendocrine prostate cancer
    (Oxford University Press, 2024) Liu, Sheng; Nam, Hye Seung; Zeng, Ziyu; Deng, Xuehong; Pashaei, Elnaz; Zang, Yong; Yang, Lei; Li, Chenglong; Huang, Jiaoti; Wendt, Michael K.; Lu, Xin; Huang, Rong; Wan, Jun; Medical and Molecular Genetics, School of Medicine
    Prostate cancer (PCa) is the most prevalent cancer affecting American men. Castration-resistant prostate cancer (CRPC) can emerge during hormone therapy for PCa, manifesting with elevated serum prostate-specific antigen levels, continued disease progression, and/or metastasis to the new sites, resulting in a poor prognosis. A subset of CRPC patients shows a neuroendocrine (NE) phenotype, signifying reduced or no reliance on androgen receptor signaling and a particularly unfavorable prognosis. In this study, we incorporated computational approaches based on both gene expression profiles and protein-protein interaction networks. We identified 500 potential marker genes, which are significantly enriched in cell cycle and neuronal processes. The top 40 candidates, collectively named CDHu40, demonstrated superior performance in distinguishing NE PCa (NEPC) and non-NEPC samples based on gene expression profiles. CDHu40 outperformed most of the other published marker sets, excelling particularly at the prognostic level. Notably, some marker genes in CDHu40, absent in the other marker sets, have been reported to be associated with NEPC in the literature, such as DDC, FOLH1, BEX1, MAST1, and CACNA1A. Importantly, elevated CDHu40 scores derived from our predictive model showed a robust correlation with unfavorable survival outcomes in patients, indicating the potential of the CDHu40 score as a promising indicator for predicting the survival prognosis of those patients with the NE phenotype. Motif enrichment analysis on the top candidates suggests that REST and E2F6 may serve as key regulators in the NEPC progression.
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    Comparative Analysis of 3D Culture Methodologies in Prostate Cancer Cells
    (bioRxiv, 2025-03-13) Foster, Ella; Wardhana, Oliver; Zeng, Ziyu; Lu, Xin; Medicine, School of Medicine
    Three-dimensional (3D) cell culture models are increasingly utilized in cancer research to better replicate in vivo tumor microenvironments. This study examines the effects of different 3D scaffolding materials, including Matrigel, GelTrex, and the plant-based GrowDex, on prostate cancer cell lines, with a particular emphasis on neuroendocrine prostate cancer (NEPC). Four cell lines (LNCaP, LASCPC-01, PC-3, and KUCaP13) were cultured in these scaffolds to evaluate spheroid formation, cell viability, and gene expression. The results revealed that while all scaffolds supported cell viability, spheroid formation varied significantly: Matrigel promoted the most robust spheroids, especially for LASCPC-01, whereas GrowDex exhibited limitations for certain cell lines. Gene expression analysis indicated a consistent reduction in androgen receptor (AR) expression in LNCaP cells across all scaffolds, suggesting a potential shift towards a neuroendocrine phenotype. However, the expression of neuroendocrine markers varied depending on the scaffold and culture method, with the mini-domes method in Matrigel leading to decreased expression of both castration-resistant prostate cancer (CRPC) and NEPC markers. These findings highlight the scaffold-dependent variability in 3D culture outcomes and emphasize the need for standardized methodologies to ensure consistency and relevance in prostate cancer research.
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    Differential Targeting of Gr-MDSCs, T Cells and Prostate Cancer Cells by Dactolisib and Dasatinib
    (MDPI, 2020-04) Liu, Guoqiang; Jin, Zhijian; Lu, Xin; Medicine, School of Medicine
    Granulocytic myeloid-derived suppressor cells (Gr-MDSCs) promote immune evasion and resistance to immunotherapeutics in a variety of malignancies. Our previous study showed that dual PI3K/mTOR inhibitor Dactolisib impaired the viability and immunosuppressive function of Gr-MDSCs, and significantly synergized with immune checkpoint blockade (ICB) antibodies targeting PD1 and CTLA4 to eradicate metastatic castration-resistant prostate cancer (CRPC) in a preclinical transgenic mouse model. On the contrary, tyrosine kinase inhibitor Dasatinib diminished tumor-infiltrating T lymphocytes and showed no synergic activity with ICB. The understanding of the distinct effects of Dactolisib and Dasatinib on Gr-MDSCs, T cells and prostate neoplastic cells is inadequate, limiting the clinical translation of the combination immunotherapy. To address this question, we applied Reverse Phase Protein Array (RPPA) to profile 297 proteins and protein phosphorylation sites of Gr-MDSCs, T cells and prostate cancer cells isolated from the CRPC model. We found cell type-specific protein expression patterns and highly selective targets by the two drugs, including preferential inhibition of phospho-4E-BP1 in Gr-MDSCs by Dactolisib and preferential suppression of phospho-Src and phospho-p38 MAPK in T cells. Furthermore, transcriptomic profiling of Gr-MDSCs treated with the two inhibitors revealed downregulation of mitochondrial respiration pathways by Dactolisib but not Dasatinib. Overall, these results provide important mechanistic insight into the efficacious combination of Dactolisib and ICB as well as the detrimental effect of Dasatinib on anti-tumor immunity.
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    Effective combinatorial immunotherapy for penile squamous cell carcinoma
    (Springer Nature, 2020-05-01) Huang, Tianhe; Cheng, Xi; Chahoud, Jad; Sarhan, Ahmed; Tamboli, Pheroze; Rao, Priya; Guo, Ming; Manyam, Ganiraju; Zhang, Li; Xiang, Yu; Han, Leng; Shang, Xiaoying; Deng, Pingna; Luo, Yanting; Lu, Xuemin; Feng, Shan; Ferrer, Magaly Martinez; Wang, Y. Alan; DePinho, Ronald A.; Pettaway, Curtis A.; Lu, Xin; Medicine, School of Medicine
    Penile squamous cell carcinoma (PSCC) accounts for over 95% of penile malignancies and causes significant mortality and morbidity in developing countries. Molecular mechanisms and therapies of PSCC are understudied, owing to scarcity of laboratory models. Herein, we describe a genetically engineered mouse model of PSCC, by co-deletion of Smad4 and Apc in the androgen-responsive epithelium of the penis. Mouse PSCC fosters an immunosuppressive microenvironment with myeloid-derived suppressor cells (MDSCs) as a dominant population. Preclinical trials in the model demonstrate synergistic efficacy of immune checkpoint blockade with the MDSC-diminishing drugs cabozantinib or celecoxib. A critical clinical problem of PSCC is chemoresistance to cisplatin, which is induced by Pten deficiency on the backdrop of Smad4/Apc co-deletion. Drug screen studies informed by targeted proteomics identify a few potential therapeutic strategies for PSCC. Our studies have established what we believe to be essential resources for studying PSCC biology and developing therapeutic strategies.
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    Enhancing immune checkpoint blockade therapy of genitourinary malignancies by co-targeting PMN-MDSCs
    (Elsevier, 2022) Lu, Xuemin; Lu, Xin; Medicine, School of Medicine
    Immune checkpoint blockade (ICB) as a powerful immunotherapy has transformed cancer treatment. The application of ICB to genitourinary malignancies has generated substantial clinical benefits for patients with advanced kidney cancer or bladder cancer, yet very limited response to ICB therapy was observed from metastatic castration-resistant prostate cancer. The efficacy of ICB in rare genitourinary tumors (e.g. penile cancer) awaits results from ongoing clinical trials. A potential barrier for ICB is tumor-infiltrating polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) with their functions and mechanisms recently revealed. Preclinical studies suggest that successful therapeutic inhibition of PMN-MDSCs synergizes effectively with ICB to eradicate ICB-refractory genitourinary malignancies.
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    Evaluation of cancer immunotherapy using mini-tumor chips
    (Ivyspring International, 2022-05-01) Ao, Zheng; Cai, Hongwei; Wu, Zhuhao; Hu, Liya; Li, Xiang; Kaurich, Connor; Gu, Mingxia; Cheng, Liang; Lu, Xin; Guo, Feng; Pathology and Laboratory Medicine, School of Medicine
    Rationale: Predicting tumor responses to adjuvant therapies can potentially help guide treatment decisions and improve patient survival. Currently, tumor pathology, histology, and molecular profiles are being integrated into personalized profiles to guide therapeutic decisions. However, it remains a grand challenge to evaluate tumor responses to immunotherapy for personalized medicine. Methods: We present a microfluidics-based mini-tumor chip approach to predict tumor responses to cancer immunotherapy in a preclinical model. By uniformly infusing dissociated tumor cells into isolated microfluidic well-arrays, 960 mini-tumors could be uniformly generated on-chip, with each well representing the ex vivo tumor niche that preserves the original tumor cell composition and dynamic cell-cell interactions and autocrine/paracrine cytokines. Results: By incorporating time-lapse live-cell imaging, our mini-tumor chip allows the investigation of dynamic immune-tumor interactions as well as their responses to cancer immunotherapy (e.g., anti-PD1 treatment) in parallel within 36 hours. Additionally, by establishing orthotopic breast tumor models with constitutive differential PD-L1 expression levels, we showed that the on-chip interrogation of the primary tumor's responses to anti-PD1 as early as 10 days post tumor inoculation could predict the in vivo tumors' responses to anti-PD1 at the endpoint of day 24. We also demonstrated the application of this mini-tumor chip to interrogate on-chip responses of primary tumor cells isolated from primary human breast and renal tumor tissues. Conclusions: Our approach provides a simple, quick-turnaround solution to measure tumor responses to cancer immunotherapy.
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    HSF1 Inhibits Antitumor Immune Activity in Breast Cancer by Suppressing CCL5 to Block CD8+ T-cell Recruitment
    (American Association for Cancer Research, 2024) Jacobs, Curteisha; Shah, Sakhi; Lu, Wen-Cheng; Ray, Haimanti; Wang, John; Hockaden, Natasha; Sandusky, George; Nephew, Kenneth P.; Lu, Xin; Cao, Sha; Carpenter, Richard L.; Pathology and Laboratory Medicine, School of Medicine
    Heat shock factor 1 (HSF1) is a stress-responsive transcription factor that promotes cancer cell malignancy. To provide a better understanding of the biological processes regulated by HSF1, here we developed an HSF1 activity signature (HAS) and found that it was negatively associated with antitumor immune cells in breast tumors. Knockdown of HSF1 decreased breast tumor size and caused an influx of several antitumor immune cells, most notably CD8+ T cells. Depletion of CD8+ T cells rescued the reduction in growth of HSF1-deficient tumors, suggesting HSF1 prevents CD8+ T-cell influx to avoid immune-mediated tumor killing. HSF1 suppressed expression of CCL5, a chemokine for CD8+ T cells, and upregulation of CCL5 upon HSF1 loss significantly contributed to the recruitment of CD8+ T cells. These findings indicate that HSF1 suppresses antitumor immune activity by reducing CCL5 to limit CD8+ T-cell homing to breast tumors and prevent immune-mediated destruction, which has implications for the lack of success of immune modulatory therapies in breast cancer. Significance: The stress-responsive transcription factor HSF1 reduces CD8+ T-cell infiltration in breast tumors to prevent immune-mediated killing, indicating that cellular stress responses affect tumor-immune interactions and that targeting HSF1 could improve immunotherapies.
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    Hsp90β inhibition upregulates interferon response and enhances immune checkpoint blockade therapy in murine tumors
    (Frontiers, 2022-10-19) Rahmy, Sharif; Mishra, Sanket J.; Murphy, Sean; Blagg, Brian S. J.; Lu, Xin; Biology, School of Science
    Response resistance to the immune checkpoint blockade (ICB) immunotherapy remains a major clinical challenge that may be overcome through the rational combination of ICB and specific targeted therapeutics. One emerging combination strategy is based on sensitizing ICB-refractory tumors with antagonists of 90kD heat shock protein (Hsp90) that target all four isoforms. However, pan-Hsp90 inhibitors are limited by the modest efficacy, on-target and off-tumor toxicities, and induction of the heat shock response (HSR) that overrides the effect of Hsp90 inhibition. Recently, we developed Hsp90β-selective inhibitors that were cytotoxic to cancer cells but did not induce HSR in vitro. Here, we report that the Hsp90β inhibitor NDNB1182 downregulated CDK4 (an Hsp90β-dependent client protein) and induced the expression of endogenous retroviral elements and interferon-stimulated genes. In syngeneic mouse models of prostate cancer and breast cancer, NDNB1182 significantly augmented the efficacy of ICB therapy. Furthermore, NDNB1182 showed superior tolerability to the pan-Hsp90 inhibitor Ganetespib in mice. Our findings provide evidence that Hsp90β inhibition is a potentially effective and safe regimen to combine with ICB to treat immunotherapy-refractory solid tumors.
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    Hsp90β inhibition upregulates interferon response and enhances immune checkpoint blockade therapy in murine tumors
    (Frontiers Media, 2022-10-20) Rahmy, Sharif; Mishra, Sanket J.; Murphy, Sean; Blagg, Brian S. J.; Lu, Xin; Medicine, School of Medicine
    Response resistance to the immune checkpoint blockade (ICB) immunotherapy remains a major clinical challenge that may be overcome through the rational combination of ICB and specific targeted therapeutics. One emerging combination strategy is based on sensitizing ICB-refractory tumors with antagonists of 90kD heat shock protein (Hsp90) that target all four isoforms. However, pan-Hsp90 inhibitors are limited by the modest efficacy, on-target and off-tumor toxicities, and induction of the heat shock response (HSR) that overrides the effect of Hsp90 inhibition. Recently, we developed Hsp90β-selective inhibitors that were cytotoxic to cancer cells but did not induce HSR in vitro. Here, we report that the Hsp90β inhibitor NDNB1182 downregulated CDK4 (an Hsp90β-dependent client protein) and induced the expression of endogenous retroviral elements and interferon-stimulated genes. In syngeneic mouse models of prostate cancer and breast cancer, NDNB1182 significantly augmented the efficacy of ICB therapy. Furthermore, NDNB1182 showed superior tolerability to the pan-Hsp90 inhibitor Ganetespib in mice. Our findings provide evidence that Hsp90β inhibition is a potentially effective and safe regimen to combine with ICB to treat immunotherapy-refractory solid tumors.