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Accumulating evidence has demonstrated that drug resistance can be acquired in cancer through the repopulation of tumors by cancer stem cell (CSC) expansion. Here, we investigated mechanisms driving resistance and CSC repopulation in hepatocellular carcinoma (HCC) as a cancer model using two drug-resistant, patient-derived tumor xenografts that mimicked the development of acquired resistance to sorafenib or lenvatinib treatment observed in patients with HCC. RNA sequencing analysis revealed that cholesterol biosynthesis was most commonly enriched in the drug-resistant xenografts. Comparison of the genetic profiles of CD133+ stem cells and CD133− bulk cells from liver regeneration and HCC mouse models showed that the cholesterol pathway was preferentially upregulated in liver CSCs compared with normal liver stem cells. Consistently, SREBP2-mediated cholesterol biosynthesis was crucial for the augmentation of liver CSCs, and loss of SREBP2 conferred sensitivity to tyrosine kinase inhibitors, suggesting a role in regulation of acquired drug resistance in HCC. Similarly, exogenous cholesterol-treated HCC cells showed enhanced cancer stemness abilities and drug resistance. Mechanistically, caspase-3 (CASP3) mediated cleavage of SREBP2 from the endoplasmic reticulum to promote cholesterol biosynthesis, which consequently caused resistance to sorafenib/lenvatinib treatment by driving activation of the sonic hedgehog signaling pathway. Simvastatin, an FDA-approved cholesterol-lowering drug, not only suppressed HCC tumor growth but also sensitized HCC cells to sorafenib. These findings demonstrate that CSC populations in HCC expand via CASP3-dependent, SREBP2-mediated cholesterol biosynthesis in response to tyrosine kinase inhibitor therapy and that targeting cholesterol biosynthesis can overcome acquired drug resistance.Significance:This study finds that cholesterol biosynthesis supports the expansion of cancer stem cell populations to drive resistance to tyrosine kinase inhibitor therapy in hepatocellular carcinoma, identifying potential therapeutic approaches for improving cancer treatment.

Oncomine analysis shows IRAK1 overexpression in cancers of breast, bladder, brain, colon, lung and ovary

Suppl Materials, Figure Legends 1-7 and Tables showing clinico-pathological correlation of endogenous IRAK1, the effect of IRAK1 alternations on tumorigenicity as well as pathway analysis of HCC cells with or without IRAK1 suppressed

The survival benefit derived from sorafenib treatment for patients with hepatocellular carcinoma (HCC) is modest due to acquired resistance. Targeting cancer stem cells (CSC) is a possible way to reverse drug resistance, however, inhibitors that specifically target liver CSCs are limited. In this study, we established two sorafenib-resistant, patient-derived tumor xenografts (PDX) that mimicked development of acquired resistance to sorafenib in patients with HCC. RNA-sequencing analysis of sorafenib-resistant PDXs and their corresponding mock controls identified EPH receptor B2 (EPHB2) as the most significantly upregulated kinase. EPHB2 expression increased stepwise from normal liver tissue to fibrotic liver tissue to HCC tissue and correlated with poor prognosis. Endogenous EPHB2 knockout showed attenuation of tumor development in mice. EPHB2 regulated the traits of liver CSCs; similarly, sorted EPHB2High HCC cells were endowed with enhanced CSC properties when compared with their EPHB2-Low counterparts. Mechanistically, EPHB2 regulated cancer stemness and drug resistance by driving the SRC/AKT/GSK3β/β-catenin signaling cascade, and EPHB2 expression was regulated by TCF1 via promoter activation, forming a positive Wnt/β-catenin feedback loop. Intravenous administration of rAAV-8-shEPHB2 suppressed HCC tumor growth and significantly sensitized HCC cells to sorafenib in an NRAS/AKT-driven HCC immunocompetent mouse model. Targeting a positive feedback loop involving the EPHB2/β-catenin axis may be a possible therapeutic strategy to combat acquired drug resistance in HCC.Significance:This study identifies a EPHB2/β-catenin/TCF1 positive feedback loop that augments cancer stemness and sorafenib resistance in HCC, revealing a targetable axis to combat acquired drug resistance in HCC.

Supplementary Data from Caspase-3–Induced Activation of SREBP2 Drives Drug Resistance via Promotion of Cholesterol Biosynthesis in Hepatocellular Carcinoma

Frequent relapse and drug resistance in patients with hepatocellular carcinoma (HCC) can be attributed to the existence of tumor-initiating cells (TIC) within the tumor bulk. Therefore, targeting liver TICs may improve the prognosis of these patients. From transcriptome sequencing of 16 pairs of clinical HCC samples, we report that interleukin-1 receptor-associated kinase 1 (IRAK1) in the TLR/IRAK pathway is significantly upregulated in HCC. IRAK1 overexpression in HCC was further confirmed at the mRNA and protein levels and correlated with advanced tumor stages and poor patient survival. Interestingly, IRAK4, an upstream regulator of IRAK1, was also consistently upregulated. IRAK1 regulated liver TIC properties, including self-renewal, tumorigenicity, and liver TIC marker expression. IRAK1 inhibition sensitized HCC cells to doxorubicin and sorafenib treatment in vitro via suppression of the apoptotic cascade. Pharmacological inhibition of IRAK1 with a specific IRAK1/4 kinase inhibitor consistently suppressed liver TIC populations. We identified aldo-keto reductase family 1 member 10 (AKR1B10) as a novel downstream target of IRAK1, which was found to be overexpressed in HCC and significantly correlated with IRAK1 expression. Knockdown of AKR1B10 negated IRAK1-induced TIC functions via modulation of the AP-1 complex. Inhibition of IRAK1/4 inhibitor in combination with sorafenib synergistically suppressed tumor growth in an HCC xenograft model. In conclusion, targeting the IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway may be a potential therapeutic strategy against HCC.Significance: IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway regulates cancer stemness and drug resistance and may be a novel therapeutic target in HCC. Cancer Res; 78(9); 2332–42. ©2018 AACR.

The survival benefit derived from sorafenib treatment for patients with hepatocellular carcinoma (HCC) is modest due to acquired resistance. Targeting cancer stem cells (CSC) is a possible way to reverse drug resistance, however, inhibitors that specifically target liver CSCs are limited. In this study, we established two sorafenib-resistant, patient-derived tumor xenografts (PDX) that mimicked development of acquired resistance to sorafenib in patients with HCC. RNA-sequencing analysis of sorafenib-resistant PDXs and their corresponding mock controls identified EPH receptor B2 (EPHB2) as the most significantly upregulated kinase. EPHB2 expression increased stepwise from normal liver tissue to fibrotic liver tissue to HCC tissue and correlated with poor prognosis. Endogenous EPHB2 knockout showed attenuation of tumor development in mice. EPHB2 regulated the traits of liver CSCs; similarly, sorted EPHB2High HCC cells were endowed with enhanced CSC properties when compared with their EPHB2-Low counterparts. Mechanistically, EPHB2 regulated cancer stemness and drug resistance by driving the SRC/AKT/GSK3β/β-catenin signaling cascade, and EPHB2 expression was regulated by TCF1 via promoter activation, forming a positive Wnt/β-catenin feedback loop. Intravenous administration of rAAV-8-shEPHB2 suppressed HCC tumor growth and significantly sensitized HCC cells to sorafenib in an NRAS/AKT-driven HCC immunocompetent mouse model. Targeting a positive feedback loop involving the EPHB2/β-catenin axis may be a possible therapeutic strategy to combat acquired drug resistance in HCC. Significance: This study identifies a EPHB2/β-catenin/TCF1 positive feedback loop that augments cancer stemness and sorafenib resistance in HCC, revealing a targetable axis to combat acquired drug resistance in HCC.

Aging biology is a promising and burgeoning research area that can yield dual-purpose pathways and protein targets that may impact multiple diseases, while retarding or possibly even reversing age-associated processes. One widely used approach to classify a multiplicity of mechanisms driving the aging process is the hallmarks of aging. In addition to the classic nine hallmarks of aging, processes such as extracellular matrix stiffness, chronic inflammation and activation of retrotransposons are also often considered, given their strong association with aging. In this study, we used a variety of target identification and prioritization techniques offered by the AI-powered PandaOmics platform, to propose a list of promising novel aging-associated targets that may be used for drug discovery. We also propose a list of more classical targets that may be used for drug repurposing within each hallmark of aging. Most of the top targets generated by this comprehensive analysis play a role in inflammation and extracellular matrix stiffness, highlighting the relevance of these processes as therapeutic targets in aging and age-related diseases. Overall, our study reveals both high confidence and novel targets associated with multiple hallmarks of aging and demonstrates application of the PandaOmics platform to target discovery across multiple disease areas.

Accumulating evidence has demonstrated that drug resistance can be acquired in cancer through the repopulation of tumors by cancer stem cell (CSC) expansion. Here, we investigated mechanisms driving resistance and CSC repopulation in hepatocellular carcinoma (HCC) as a cancer model using two drug-resistant, patient-derived tumor xenografts that mimicked the development of acquired resistance to sorafenib or lenvatinib treatment observed in patients with HCC. RNA sequencing analysis revealed that cholesterol biosynthesis was most commonly enriched in the drug-resistant xenografts. Comparison of the genetic profiles of CD133+ stem cells and CD133− bulk cells from liver regeneration and HCC mouse models showed that the cholesterol pathway was preferentially upregulated in liver CSCs compared with normal liver stem cells. Consistently, SREBP2-mediated cholesterol biosynthesis was crucial for the augmentation of liver CSCs, and loss of SREBP2 conferred sensitivity to tyrosine kinase inhibitors, suggesting a role in regulation of acquired drug resistance in HCC. Similarly, exogenous cholesterol-treated HCC cells showed enhanced cancer stemness abilities and drug resistance. Mechanistically, caspase-3 (CASP3) mediated cleavage of SREBP2 from the endoplasmic reticulum to promote cholesterol biosynthesis, which consequently caused resistance to sorafenib/lenvatinib treatment by driving activation of the sonic hedgehog signaling pathway. Simvastatin, an FDA-approved cholesterol-lowering drug, not only suppressed HCC tumor growth but also sensitized HCC cells to sorafenib. These findings demonstrate that CSC populations in HCC expand via CASP3-dependent, SREBP2-mediated cholesterol biosynthesis in response to tyrosine kinase inhibitor therapy and that targeting cholesterol biosynthesis can overcome acquired drug resistance. Significance: This study finds that cholesterol biosynthesis supports the expansion of cancer stem cell populations to drive resistance to tyrosine kinase inhibitor therapy in hepatocellular carcinoma, identifying potential therapeutic approaches for improving cancer treatment.

Frequent relapse and drug resistance in patients with hepatocellular carcinoma (HCC) can be attributed to the existence of tumor-initiating cells (TIC) within the tumor bulk. Therefore, targeting liver TICs may improve the prognosis of these patients. From transcriptome sequencing of 16 pairs of clinical HCC samples, we report that interleukin-1 receptor-associated kinase 1 (IRAK1) in the TLR/IRAK pathway is significantly upregulated in HCC. IRAK1 overexpression in HCC was further confirmed at the mRNA and protein levels and correlated with advanced tumor stages and poor patient survival. Interestingly, IRAK4, an upstream regulator of IRAK1, was also consistently upregulated. IRAK1 regulated liver TIC properties, including self-renewal, tumorigenicity, and liver TIC marker expression. IRAK1 inhibition sensitized HCC cells to doxorubicin and sorafenib treatment in vitro via suppression of the apoptotic cascade. Pharmacological inhibition of IRAK1 with a specific IRAK1/4 kinase inhibitor consistently suppressed liver TIC populations. We identified aldo-keto reductase family 1 member 10 (AKR1B10) as a novel downstream target of IRAK1, which was found to be overexpressed in HCC and significantly correlated with IRAK1 expression. Knockdown of AKR1B10 negated IRAK1-induced TIC functions via modulation of the AP-1 complex. Inhibition of IRAK1/4 inhibitor in combination with sorafenib synergistically suppressed tumor growth in an HCC xenograft model. In conclusion, targeting the IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway may be a potential therapeutic strategy against HCC. Significance: IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway regulates cancer stemness and drug resistance and may be a novel therapeutic target in HCC. Cancer Res; 78(9); 2332–42. ©2018 AACR.

Solid evidence shows that tumor-initiating cells (T-ICs) are the root of tumor relapse and drug resistance, which lead to a poor prognosis in patients with hepatocellular carcinoma (HCC). Through an in vitro liver T-IC enrichment approach, we identified nuclear factor (erythroid-derived 2)-like 2 (NRF2) as a transcription regulator that is significantly activated in enriched liver T-IC populations. In human HCCs, NRF2 was found to be overexpressed, which was associated with poor patient survival. Through a lentiviral based knockdown approach, NRF2 was found to be critical for regulating liver T-IC properties, including self-renewal, tumorigenicity, drug resistance and expression of liver T-IC markers. Furthermore, we found that ROS-induced NRF2 activation regulates sorafenib resistance in HCC cells. Mechanistically, NRF2 was found to physically bind to the promoter of sonic hedgehog homolog (SHH), which triggers activation of the sonic hedgehog pathway. The effect of NRF2 knockdown was eliminated upon administration of recombinant SHH, demonstrating that NRF2 mediated T-IC function via upregulation of SHH expression. Our study suggests a novel regulatory mechanism for the canonical sonic hedgehog pathway that may function through the NRF2/SHH/GLI signaling axis, thus mediating T-IC phenotypes.

Background An increasing number of breast cancer patients in Asian countries has been found to consume dietary supplements including phytoestrogen-rich Chinese herbal medicines with an expectation to alleviate the side effects of conventional cancer therapies. Purpose The question of whether estrogenic Chinese herbal medicines are beneficial or detrimental to the health of breast cancer patients remains uncertain. Study Design The present study aimed at establishing a systematic approach to look at the safety profiles of estrogenic Chinese herbal medicines (CHM). Methods The effects of estrogenic CHM on the growth of human breast cancer cells as well as the progression of breast tumors in mice have been investigated. Results Our results demonstrated that among 10 selected estrogenic CHM, the aqueous extracts of Cistanche deserticola (CD) and Dioscorea opposita (DO) at 0.4 to 1.6 mg/ml significantly stimulated cell viability in both estrogen receptor (ER)-positive (MDA-MB-361 and MCF-7) and ER-negative (SKBR3 and MDA-MB-231) breast cancer cells. However, results from animal studies showed that no significant difference was found on the size of mouse 4T1 breast tumors in CD- and DO-treated mice when compared with the control group, while the number of proliferative cells were found to be increased in DO-treated group. Besides, CD and DO treatments induced significant immunomodulatory effects on 4T1 tumor-bearing mice by increasing the production of cytokines IL-2 and IFN-γ and modulation of regulatory T-cells. Furthermore, CD and DO treatments did not stimulate, but in fact suppressed human triple-negative MDA-MB-231 breast xenografts growth in immunodeficiency mice. Conclusion The considerable concerns on the use of CD and DO in breast cancer patients could be relieved to some extents upon the findings of this pre-clinical study. The potential harmful effects of estrogenic Chinese herbal medicines on breast cancer growth should be verified in both cell-based and tumor-bearing mice models.

Cyclopeptide RA-V has potent anti-tumor and anti-angiogenic activities, but its potential anti-metastatic activity is unknown. Cancer cells acquire invasive ability to degrade and adhere to extracellular matrix (ECM), allowing them to migrate to adjacent tissues and ultimately metastasize. Hence, the present study aimed to investigate the effects of RA-V on cell adhesion, migration, invasion and matrix degradation, and its underlying mechanism in two human breast cancer cell lines MCF-7 (ER-positive) and MDA-MB-231 (ER-negative). Our results demonstrated that RA-V (12.5nM) can significantly inhibit breast cancer cell adhesion and migration via interfering cofilin signaling and chemokine receptors involved in cell migration. RA-V reduced the expressions of vascular intracellular adhesion molecule (VCAM), intracellular adhesion molecule (ICAM), focal adhesion kinase (FAK) and integrins. The activities and expressions of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) and urokinase-type of plasminogen activator (uPA) were also inhibited by RA-V. Furthermore, RA-V inhibits the expressions of EGFR, PI3K/AKT and NF-κB signaling molecules, and reduces the binding of β-estradiol to ER via affecting binding ability of ER in MCF-7 cells. RA-V inhibits breast cancer cell migration, adhesion and ECM degradation in vitro, implying that RA-V is a potential anti-metastatic agent in breast cancer, and likely acts via PI3K/AKT and NF-κB signaling pathways in both ER-positive and ER-negative breast cancer cells.

Cancer stem-like cells (CSC) are regarded as the source of tumour origins, metastasis and drug resistance, and limits current treatment regimens. Previously, we reported the first study of the anti-angiogenic and anti-tumour activities of 4-vinylphenol. To further examine the therapeutic role of 4-vinylphenol, the inhibitory effects of 4-vinylphenol on cancer stemness, drug resistance and metastasis in breast cancer were investigated in the present study. We enriched parental MDA-MB-231 cells with CSCs in serum-free medium to give spheroids. The effects of 4-vinylphenol on cancer stemness, metastasis and drug resistance in CSC-enriched MDA-MB-231 cells were studied in vitro and in vivo. CSC-enriched MDA-MB-231 cells demonstrated higher tumorigenic and metastatic potential. 4-Vinylphenol reduced spheroid formation and ALDH1 expression in CSC-enriched cultures, revealing its inhibitory effects on the traits of CSCs. 4-Vinylphenol suppressed colony formation and cell proliferation. 4VP also inhibited in vitro invasion and in vivo metastasis in zebrafish model. Our results showed that it reduced vimentin expression, suppressed cell migration, affected the expression and/or activity of MMPs, TIMPs and uPA. In addition, the expressions of caspases 3 and 9 were increased upon its treatment, and surprisingly, prolonged treatment did not confer cancer cells with drug resistance to 4-vinylphenol. 4-Vinylphenol probably exhibited its anti-cancer activities via beta-catenin, EGFR and AKT signaling pathways. 4-Vinylphenol was shown to inhibit metastasis and cancer stemness in CSC-enriched breast cancer cells. Since conventional therapies not targeting CSCs possibly lead to failure to eliminate cancer, 4-vinylphenol is a highly potential therapeutic agent for breast cancer patients.

Background: Angelica sinensis (AS) has long been regarded to stimulate breast cancer growth, hence the use of AS in breast cancer patients remains a major concern for both patients and practitioners. Since safety studies of herbs would be unethical to carry out in patients, the present study aimed to investigate the potential unsafe effects of AS in a systematic pre-clinical approach. Methods: Human breast cancer cells, breast orthotopic tumor-bearing mouse models as well as primary breast cancer cells from patients' tumors were used to evaluate the effect of AS hot water extract on the progression of breast tumors and/or growth of breast cancer cells. Results: We showed that AS is not that stimulatory in breast cancer both in vitro and in vivo, though AS should still be used with caution in estrogen receptor-positive breast cancer patients. This novel approach of applying breast cancer cell lines, xenograft and syngeneic tumors models, as well as primary breast cancer cells from patients' tumors in Chinese medicines safety evaluation was proven feasible. Conclusions: Our finding is important information for patients, Chinese medicine practitioners and clinicians on the safety use of AS in breast cancer, which will affect future clinical practice. Funding Statement: This study was financially supported by Food and Health Bureau HKSAR, Health and Medical Research Fund no. 12130471. Declaration of Interests: The authors declare that there is no conflict of interest. Ethics Approval Statement: The study protocol was approved by the Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee (CREC Ref. No.: 2014.336) and Union Hospital Ethics Committee (EC Ref. No. EC013).

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. The long-term prognosis of HCC remains unsatisfactory due to high recurrence rates and chemoresistance. Solid evidence shows that tumor-initiating cells (T-ICs) are the root of tumor relapse and drug resistance, which led to poor prognosis of patients with hepatocellular carcinoma (HCC). Therefore, identification of crucial transcriptional regulator in liver T-IC may improve the prognosis of these patients. Through in vitro liver T-IC enrichment approach, we identified Nuclear Factor (Erythroid-Derived 2)-Like 2 (NRF2) as transcriptions regulator be significantly upregulated in enriched liver T-IC populations. NRF2 regulated liver T-IC properties including self-renewal, tumorigenicity, and liver T-IC marker expression and significantly affected patients’ clinical outcome. Furthermore, NRF2 repression led to sensitization to doxorubicin and 5-FU treatment. Furthermore, we found that ROS-induced NRF2 activation regulates sorafenib resistance of HCC cells. Mechanistically, NRF2 was found to physically bind to promoter SHH, which triggers activation of sonic hedgehog pathway. NRF2 was significantly correlated with SHH expression, which was associated with poor patient’s survival. The effect of NRF2 knockdown was eliminated upon administration of recombinant SHH, demonstrating that NRF2 mediated the TIC function via upregulation of SHH expression. Our study suggested a novel regulatory mechanism for the canonical sonic hedgehog pathway that may function through NRF2/SHH/GLI signaling axis, thus mediating T-IC phenotypes. Targeting NRF2 mediated signaling cascade alone or in combination with other treatment modalities may be a new a potential therapeutic approach for treatment of HCC. Citation Format: Hoi Wing Leung, Eunice Yuen Ting Lau, Kin Wah Lee. NRF2/SHH signaling cascade promotes tumor-initiating cell lineage and drug resistance in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4679.

Background & Aims We investigated the functional role and clinical significance of stearoyl-CoA desaturase-1 ( SCD1 ) mediated endoplasmic reticulum (ER) stress in regulating liver tumor-initiating cells (T-ICs) and sorafenib resistance, with the aim of developing a novel therapeutic strategy against hepatocellular carcinomas (HCCs). Methods We evaluated the clinic-pathological relevance of SCD1 and its correlation with sorafenib resistance in large cohorts of HCC clinical samples by qPCR and immunohistochemical analyses. Lentiviral-based overexpression and knockdown approaches were performed to characterize the functional roles of SCD1 in regulating liver T-ICs and sorafenib resistance. Molecular pathways mediating the phenotypic alterations were identified through RNA sequencing analysis and functional rescue experiments. The combinatorial effect of SCD1 inhibition and sorafenib was tested using a patient-derived tumor xenograft (PDTX) model. Results SCD1 overexpression was found in HCC, which was associated with shorter disease-free survival ( p = 0.008, log rank test). SCD1 was found to regulate the populations of liver T-ICs; while its suppression by a SCD1 inhibitor suppressed liver T-ICs and sorafenib resistance. Interestingly, SCD1 was markedly upregulated in our established sorafenib-resistant PDTX model, and its overexpression predicts the clinical response of HCC patients to sorafenib treatment. Suppression of SCD1 forces liver T-ICs to differentiate via ER stress-induced unfolded protein response, resulting in an enhanced sensitivity to sorafenib. The PDTX#1 model, combined with sorafenib treatment and a novel SCD1 inhibitor (SSI-4), showed a maximal growth suppressive effect. Conclusions SCD1 -mediated ER stress regulates liver T-ICs and sorafenib sensitivity. Targeting SCD1 alone or in combination with sorafenib might be a novel personalized medicine against HCC. Lay summary: In this study, SCD1 was found to play a critical role in regulating liver tumor-initiating cells and sorafenib resistance through the regulation of ER stress-mediated differentiation. Targeting SCD1 in combination with sorafenib may be a novel therapeutic strategy against liver cancer.

Bigelovin is a sesquiterpene lactone isolated from the plant Inula helianthus-aquatica which was traditionally used in cancer treatment in Yunnan, China. The potent apoptotic activities of bigelovin in human leukemia U937 cells were shown in our previous study. The present study investigated the anti-angiogenic and immunomodulatory effects of bigelovin using transgenic zebrafish Tg(fli1a:EGFP)y1 with fluorescent blood vessels and human peripheral blood mononuclear cells (PBMCs), respectively. Furthermore, the inhibitory activities of bigelovin on the human endothelial cell adhesion molecules (CAMs) were also examined. Our results showed that the growth of subintestinal vessels of the bigelovin-treated zebrafish embryos was significantly inhibited and the gene expressions in angiogenesis signaling pathways (e.g. Ang2 and Tie2) of the zebrafish were down-regulated after bigelovin treatment. Besides, the proliferation and Th1 cytokines productions (e.g. IFN-γ, IL-2 and IL-12) were suppressed in bigelovin-treated PBMCs. On the other hand, bigelovin was shown to significantly inhibit the human monocyte adhesion to human endothelial cells and the gene expressions of inflammation-related CAMs (e.g. ICAM-1, VCAM-1 and E-selectin) were significantly down-regulated in bigelovin-treated human endothelial cells. In summary, our data provide the first evidence that bigelovin possesses anti-angiogenic and immunomodulatory activities, suggesting bigelovin may exert multi-target functions against cancer in animal models.

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. The long-term prognosis of HCC remains unsatisfactory due to high recurrence rates and chemoresistance. The efficacy of sorafenib, the only FDA-approved molecularly targeted drug in advanced hepatocellular carcinoma (HCC) is limited by acquired resistance. Increasing evidences showed that liver tumor-initiating cells (T-ICs) is the source of acquired resistance and metastasis. We have previously established sorafenib-resistant HCC cells both in vitro and PDTX models and demonstrated that these cells are endowed with enhanced T-IC properties. Interestingly, nuclear factor (erythroid-derived 2)-like 2 (NRF2) expression was elevated in these resistant cells. The transcription factor NRF2 has long been considered as a tumour suppressor, as it can regulate cellular antioxidant response to protect cells from oxidative stress, chemotherapeutic agents and radiotherapy. In HCC, NRF2 level was up-regulated, and its expression was correlated with tumor differentiation, metastasis, and tumor size, revealing its oncogenic role. By lentiviral based knockdown approach, we found that NRF2 repression suppressed liver T-IC properties including self-renewal, in vivo tumorigenicity, HCC invasiveness and expression of liver T-IC markers. In addition, we found that NRF2 repression not only sensitized HCC cells to sorafenib but also to other chemotherapeutic drugs including doxorubicin and fluorouracil. Mechanistically, the signaling cascade related to sonic hedgehog pathway was greatly suppressed in NRF2 knockdown HCC cells, when compared with control counterparts. Collectively, NRF2 was involved in drug resistance, invasion and migration, tumorigenicity and self-renewal via regulating T-IC properties at least in part through direct regulation of sonic hedgehog pathway in HCC. Targeting NRF2 mediated signaling cascade alone or in combination with other treatment modalities may be a new a potential therapeutic approach for treatment of HCC. Citation Format: Hoi Wing Leung, Terence Kin Wah Lee. Nuclear factor (erythroid-derived 2)-like 2 promotes tumor-initiating cell lineage and drug resistance in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1996.

Frequent relapse and drug resistance can be attributed to the existence of tumor-initiating cells (T-ICs) within the tumor bulk. From transcriptome sequencing of 16 pairs of clinical HCC samples, we found that Interleukin-1 receptor-associated kinase 1 (IRAK1) in the TLR/IRAK pathway was significantly upregulated in hepatocellular carcinoma (HCC). IRAK1 overexpression in HCC was further confirmed at the mRNA and protein levels and correlated with advanced tumor stages and poor patents survival. Interestingly, IRAK4, an upstream regulator of IRAK1, was also found to be consistently upregulated. We demonstrated that IRAK1 regulates liver T-IC properties, including self-renewal, tumorigenicity and liver T-IC marker expression. IRAK1 inhibition sensitized the HCC cells to doxorubicin and sorafenib treatment in vitro through the suppression of the apoptotic cascade. Pharmacological inhibition of IRAK1 with a specific IRAK1/4 kinase inhibitor consistently suppressed liver T-IC populations. Through RNA sequencing analysis by comparing gene expression profiles between IRAK1-knockdown and control cells, we identified Aldo-Keto Reductase Family 1 Member 10 (AKR1B10) as a novel downstream target of IRAK1. Clinically, AKR1B10 was found to be overexpressed in HCC, which was significantly correlated with IRAK1 expression. Functional analysis demonstrated that knockdown of AKR1B10 negated the IRAK1-induced T-IC functions via modulation of the AP-1 complex. Using an HCC xenograft model, we found that an IRAK1/4 inhibitor in combination with sorafenib synergistically suppressed the tumor growth. In conclusion, targeting the IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway may be a potential therapeutic strategy against HCC. Citation Format: Bowie Yik Ling Cheng, Doris Hoi Wing Leung, Eunice Yuen Ting Lau, Irene Oi Lin Ng, Kin Wah Lee. IRAK1 augments cancer stemness and drug resistance via the AP-1/AKR1B10 signaling cascade in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1986.

Cancer cells acquire invasive ability to degrade and adhere to extracellular matrix (ECM) and migrate to adjacent tissues. This ultimately results metastasis. Hence, the present study investigated the in vitro effects of cyclopeptide glycoside, RA-XII on cell adhesion, invasion, proliferation and matrix degradation and its underlying mechanism in murine breast tumour cells, 4T1. The effect of RA-XII on tumour growth and metastasis in 4T1-bearing mice was also investigated. Our results showed that RA-XII inhibited tumour cell adhesion to collagen, fibronectin and laminin, RA-XII also reduced the expressions of vascular cell adhesion molecule, intracellular adhesion molecule and integrins and integrin binding. In addition, RA-XII significantly inhibited breast tumour cell migration via interfering cofilin signaling and chemokine receptors. The activities of matrix metalloproteinase-9 and urokinase-type of plasminogen activator and the expressions of ECM-associated proteinases were attenuated significantly by RA-XII. Furthermore, RA-XII induced G1 phase arrest and inhibited the expressions of cyclins and cyclin-dependent kinases. RA-XII inhibited the expressions of molecules in PI3K/AKT, NF-kappaB, FAK/pSRC, MAPK and EGFR signaling. RA-XII was also shown to have anti-tumour, anti-angiogenic and anti-metastatic activities in metastatic breast tumour-bearing mice. These findings strongly suggested that RA-XII is a potential anti-metastatic agent for breast cancer.

The pneumo- and hepato-toxicity of 4-vinylphenol (4VP), a styrene metabolite, has been previously reported. Nevertheless, the present study reported the novel anti-angiogenic activities of 4VP which was firstly isolated from the aqueous extract of a Chinese medicinal herb Hedyotis diffusa. Our results showed that 4VP at non-toxic dose effectively suppressed migration, tube formation, adhesion to extracellular matrix proteins, as well as protein and mRNA expressions of metalloproteinase-2 of human endothelial cells (HUVEC and HMEC-1). Investigation of the signal transduction revealed that 4VP down-regulated PI3K/AKT and p38 MAPK. Besides, 4VP interfered with the phosphorylation of ERK1/2, the translocation and expression of NFkappaB. In zebrafish embryo model, the new blood vessel growth was significantly blocked by 4VP (6.25–12.5 μg/mL medium). The VEGF-induced blood vessel formation in Matrigel plugs in C57BL/6 mice was suppressed by 4VP (20–100 μg/mL matrigel). In addition, the blood vessel number and tumor size were reduced by intraperitoneal 4VP (0.2–2 mg/kg) in 4T1 breast tumor-bearing BALB/c mice, with doxorubicin as positive control. Together, the in vitro and in vivo anti-angiogenic activities of 4VP were demonstrated for the first time. These findings suggest that 4VP has great potential to be further developed as an anti-angiogenic agent.

Sze K, Wong E, Leung HY, Woo J. Falls among Chinese stroke patients during rehabilitation. Arch Phys Med Rehabil 2001;82:1219-25. Objective: To investigate the incidence, circumstances, and risk factors of falls among Chinese stroke patients during inpatient rehabilitation. Design: Historical cohort study. Setting: A 25-bed stroke rehabilitation unit in Hong Kong. Participants: Six hundred seventy-seven patients admitted consecutively to the unit approximately 1 week after acute stroke. Interventions: All patients received conventional rehabilitation therapies, and a protocol to analyze the causes of falls and to advise on prevention was followed in the unit. Main Outcome Measures: A fall was defined as any unplanned "touch to the floor" of any part of a patient's body, excluding the feet. The fall rate and circumstances were studied. Demography, Abbreviated Mental Test score, Barthel Index score on admission, urinary incontinence, dysphasia, hemiplegia, hemiparesthesia, vision and hearing impairment, and the risk factors of stroke were analyzed by logistic regression for their relation to falls. Results: Seventy-eight patients (11.5%) had falls. The fall rate was 5.5 per 1000 patient days. Eighty-five percent of the falls occurred in daytime and 71% at the bedside. Moderate to severe disability on the Barthal Index admission (6–14) and dysphasia were associated with an increased risk of falls (odds ratio [OR] = 2.64; 95% confidence interval [CI], 1.26–5.51; OR=1.81; 95% CI, 1.03–3.17, respectively). Conclusions: Stroke patients in China had a significant fall rate during rehabilitation, but it was lower than rates reported in the Western stroke populations. The fall protocol followed in our unit might have reduced the incidence of repeated falls. The circumstances of falls were, however, similar. Moderate to severe disability on admission and dysphasia were 2 independent predictors for falls, and more intensive fall prevention efforts should focus on this group of patients. © 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physcial Medicine and Rehabilitation