Abstract Notch1 activation triggers significant oncogenic signaling that manifests as enhanced metastatic potential and tumorigenesis in colorectal cancer. Novel small-molecule inhibitors, mainly plant-derived analogs, have low toxicity profiles and higher bioavailability. In this study, we have developed a small molecule, ASR490, by modifying structure of naturally occurring compound Withaferin A. ASR490 showed a growth-inhibitory potential by downregulating Notch1 signaling in HCT116 and SW620 cell lines. Docking studies and thermal shift assays confirmed that ASR490 binds to Notch1, whereas no changes in Notch2 and Notch3 expression were seen in colorectal cancer cells. Notch1 governs epithelial-to-mesenchymal transition signaling and is responsible for metastasis, which was abolished by ASR490 treatment. To further confirm the therapeutic potential of ASR490, we stably overexpressed Notch1 in HCT-116 cells and determined its inhibitory potential in transfected colorectal cancer (Notch1/HCT116) cells. ASR490 effectively prevented cell growth in both the vector (P = 0.005) and Notch1 (P = 0.05) transfectants. The downregulation of Notch1 signaling was evident, which corresponded with downregulation of mesenchymal markers, including N-cadherin and β-catenin and induction of E-cadherin in HCT-116 transfectants. Intraperitoneal administration of a 1% MTD dose of ASR490 (5 mg/kg) effectively suppressed the tumor growth in control (pCMV/HCT116) and Notch1/HCT116 in xenotransplanted mice. In addition, downregulation of Notch1 and survival signaling in ASR-treated tumors confirmed the in vitro results. In conclusion, ASR490 appears to be a potent agent that can inhibit Notch1 signaling in colorectal cancer.

We investigated the efficacy of a small molecule ASR-600, an analog of Urolithin A (Uro A), on blocking androgen receptor (AR) and its splice variant AR-variant 7 (AR-V7) signaling in castration-resistant prostate cancer (CRPC). ASR-600 effectively suppressed the growth of AR + CRPC cells by inhibiting AR and AR-V7 expressions; no effect was seen in AR − CRPC and normal prostate epithelial cells. Biomolecular interaction assays revealed ASR-600 binds to the N-terminal domain of AR, which was further confirmed by immunoblot and subcellular localization studies. Molecular studies suggested that ASR-600 promotes the ubiquitination of AR and AR-V7 resulting in the inhibition of AR signaling. Microsomal and plasma stability studies suggest that ASR-600 is stable, and its oral administration inhibits tumor growth in CRPC xenografted castrated and non-castrated mice. In conclusion, our data suggest that ASR-600 enhances AR ubiquitination in both AR + and AR-V7 CRPC cells and inhibits their growth in vitro and in vivo models.

Delivering drugs directly to the inflamed intestinal sites to treat inflammatory bowel disease (IBD), particularly Crohn's and ulcerative colitis, is highly challenging. Recent advances in colitis therapy medications are expanding opportunities for improving local on-site drug availability by minimising the associated systemic side-effects. Drug delivery with targeted carrier systems has shown the potential to increase site-specificity, stability, and therapeutic efficacy. Herein, we report the development of a strong anionic charged inflammation targeted nanocarriers (IT-NCs) loaded with an immunosuppressant model drug. This system showed preferential adhesion on a charge-modified surface in vitro, and in both dextran sulfate sodium (DSS) and TNBS colitis mice in vivo models. IT-NCs showed improved colitis phenotype therapeutic efficacy in both animal models compared to free drug. Furthermore, ex vivo study of colon tissue biopsies from patients with colitis revealed that IT-NCs adhered preferentially to inflamed biopsies compared to normal. Together, our results suggest that IT-NCs have promising therapeutic potential as delivery carriers' in colitis management.

The active stages of intestinal inflammation and the pathogenesis of ulcerative colitis are associated with superficial mucosal damage and intermittent wounding that leads to epithelial barrier defects and increased permeability. The standard therapeutic interventions for colitis have focused mainly on maintaining the remission levels of the disease. Nonetheless, such treatment strategies (using anti-inflammatory, immunomodulatory agents) do not address colitis' root cause, especially the mucosal damage and dysregulated intestinal barrier functions. Restoration of barrier functionality by mucosal healing or physical barrier protecting strategies shall be considered as an initial event in the disease suppression and progression. Herein, a biphasic hyaluronan (HA) enema suspension, naïve-HA systems that protect the dysregulated gut epithelium by decreasing the inflammation, permeability, and helping in maintaining the epithelial barrier integrity in the dextran sodium sulfate-induced colitis mice model is reported. Furthermore, HA-based system modulates intestinal epithelial junctional proteins and regulatory signaling pathways, resulting in attenuation of inflammation and mucosal protection. The results suggest that HA-based system can be delivered as an enema to act as a barrier protecting system for managing distal colonic inflammatory diseases, including colitis.

Macrophages use mitochondrial lactate metabolism for ACLY-dependent histone acetylation, immune suppression, and tumor progression.

Epidemiological evidence suggests that cadmium (Cd) is one of the causative factors of prostate cancer, but the effect of Cd on benign prostatic hyperplasia (BPH) remains unclear. This study aimed to determine whether Cd exposure could malignantly transform BPH1 cells and, if so, to dissect the mechanism of action. We deciphered the molecular signaling responsible for BPH1 transformation via RNA-sequencing and determined that Cd induced the expression of zinc finger of the cerebellum 2 (ZIC2) in BPH1 cells. We noted Cd exposure increased ZIC2 expression in the Cd-transformed BPH1 cells that in turn promoted anchorage-independent spheroids and increased expression of stem cell drivers, indicating their role in stem cell renewal. Subsequent silencing of ZIC2 expression in transformed cells inhibited spheroid formation, stem cell marker expression, and tumor growth in nude mice. At the molecular level, ZIC2 interacts with the glioma-associated oncogene family (GLI) zinc finger 1 (GLI1), which activates prosurvival factors (nuclear factor NFκB, B-cell lymphoma-2 (Bcl2), as well as an X-linked inhibitor of apoptosis protein (XIAP)) signaling in Cd-exposed BPH1 cells. Conversely, overexpression of ZIC2 in BPH1 cells caused spheroid formation confirming the oncogenic function of ZIC2. ZIC2 activation and GLI1 signaling induction by Cd exposure in primary BPH cells confirmed the clinical significance of this oncogenic function. Finally, human BPH specimens had increased ZIC2 versus adjacent healthy tissues. Thus, we report direct evidence that Cd exposure induces malignant transformation of BPH via activation of ZIC2 and GLI1 signaling.

Notch1 activation triggers significant oncogenic signaling that manifests as enhanced metastatic potential and tumorigenesis in colorectal cancer. Novel small-molecule inhibitors, mainly plant-derived analogs, have low toxicity profiles and higher bioavailability. In this study, we have developed a small molecule, ASR490, by modifying structure of naturally occurring compound Withaferin A. ASR490 showed a growth-inhibitory potential by downregulating Notch1 signaling in HCT116 and SW620 cell lines. Docking studies and thermal shift assays confirmed that ASR490 binds to Notch1, whereas no changes in Notch2 and Notch3 expression were seen in colorectal cancer cells. Notch1 governs epithelial-to-mesenchymal transition signaling and is responsible for metastasis, which was abolished by ASR490 treatment. To further confirm the therapeutic potential of ASR490, we stably overexpressed Notch1 in HCT-116 cells and determined its inhibitory potential in transfected colorectal cancer (Notch1/HCT116) cells. ASR490 effectively prevented cell growth in both the vector (P = 0.005) and Notch1 (P = 0.05) transfectants. The downregulation of Notch1 signaling was evident, which corresponded with downregulation of mesenchymal markers, including N-cadherin and β-catenin and induction of E-cadherin in HCT-116 transfectants. Intraperitoneal administration of a 1% MTD dose of ASR490 (5 mg/kg) effectively suppressed the tumor growth in control (pCMV/HCT116) and Notch1/HCT116 in xenotransplanted mice. In addition, downregulation of Notch1 and survival signaling in ASR-treated tumors confirmed the in vitro results. In conclusion, ASR490 appears to be a potent agent that can inhibit Notch1 signaling in colorectal cancer.

Background Experimental reproducibility in mouse models is impacted by both genetics and environment. The generation of reproducible data is critical for the biomedical enterprise and has become a major concern for the scientific community and funding agencies alike. Among the factors that impact reproducibility in experimental mouse models is the variable composition of the microbiota in mice supplied by different commercial vendors. Less attention has been paid to how the microbiota of mice supplied by a particular vendor might change over time. Results In the course of conducting a series of experiments in a mouse model of malaria, we observed a profound and lasting change in the severity of malaria in mice infected with Plasmodium yoelii ; while for several years mice obtained from a specific production suite of a specific commercial vendor were able to clear the parasites effectively in a relatively short time, mice subsequently shipped from the same unit suffered much more severe disease. Gut microbiota analysis of frozen cecal samples identified a distinct and lasting shift in bacteria populations that coincided with the altered response of the later shipments of mice to infection with malaria parasites. Germ-free mice colonized with cecal microbiota from mice within the same production suite before and after this change followed by Plasmodium infection provided a direct demonstration that the change in gut microbiota profoundly impacted the severity of malaria. Moreover, spatial changes in gut microbiota composition were also shown to alter the acute bacterial burden following Salmonella infection, and tumor burden in a lung tumorigenesis model. Conclusion These changes in gut bacteria may have impacted the experimental reproducibility of diverse research groups and highlight the need for both laboratory animal providers and researchers to collaborate in determining the methods and criteria needed to stabilize the gut microbiota of animal breeding colonies and research cohorts, and to develop a microbiota solution to increase experimental rigor and reproducibility.

The importance of gut microbiota in human health and pathophysiology is undisputable. Despite the abundance of metagenomics data, the functional dynamics of gut microbiota in human health and disease remain elusive. Urolithin A (UroA), a major microbial metabolite derived from polyphenolics of berries and pomegranate fruits displays anti-inflammatory, anti-oxidative, and anti-ageing activities. Here, we show that UroA and its potent synthetic analogue (UAS03) significantly enhance gut barrier function and inhibit unwarranted inflammation. We demonstrate that UroA and UAS03 exert their barrier functions through activation of aryl hydrocarbon receptor (AhR)- nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent pathways to upregulate epithelial tight junction proteins. Importantly, treatment with these compounds attenuated colitis in pre-clinical models by remedying barrier dysfunction in addition to anti-inflammatory activities. Cumulatively, the results highlight how microbial metabolites provide two-pronged beneficial activities at gut epithelium by enhancing barrier functions and reducing inflammation to protect from colonic diseases.

Introduction: Inactivating p53 mutations contribute to tumor progression and treatment-resistance, resulting in poor patient survival in colorectal cancer patients (CRC). The goal of this study is to identify novel small molecules that therapeutically target mutant p53 in CRC. Methods: We analyzed the effects of small molecule (ASR458) on p53-wild type (p53-wt; HCT116) and mutant p53 (p53-mut; SW620) colon cancer cells by phenotypic, molecular and in vivo assays. Results: ASR458 treatment significantly inhibited the proliferation of both HCT116 and SW620 cells at nM concentrations. In p53-wt HCT116 cells, ASR458 caused induction of p53 that resulted in caspase-mediated cell death in both in vitro and in vivo models. On the contrary, ASR458 treatment induced ER-stress signaling (i.e., phosphorylation of ERK and eIF2-α) in p53-mut SW620 cells, which triggered ATF4 activation and subsequent induction of cascade of autophagy events (Atg family proteins, LC3B and Lamp1), causing autophagy-mediated cell death. Silencing ER stress marker ATF-4, a key regulator of autophagy, caused resistance to ASR458 and abrogated autophagy signaling in SW620 cells. This suggested that induction of ER-stress is critical for the cytotoxic effects of ASR458 in p53-mut CRC. Preliminary knockdown studies indicate that silencing of ER markers causes resistance to ASR458 in vitro, further confirming ER-stress as the mechanism of ASR458 action in p53-mut CRC. ASR458 significantly inhibited the growth of SW620 tumors in xenograft. Tissue analysis confirmed the ER-stress signaling observed in vitro. Conclusion: Our results demonstrate ASR458 as a potential therapeutic agent with distinct targets in p53-wt and p53-mut CRC. This study also suggests that ATF4 mediated autophagy in unmanaged ER stress can reduce CRC pathogenesis. Further investigation into the pharmacokinetics and pharmacodynamics of ASR458 should help clinical translation of this agent. Citation Format: Ashish Tyagi, Balaji chandrasekaran, Venkatesh Kolluru, Becca V. Baby, Alatassi Houda, Srinivasa Ramisetti, Arun Sharma, Murali Ankem, Chendil Damodaran. Endoplasmic reticulum (ER), a potential therapeutic target for mutant p53 colorectal cancer [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 4266.

Inflammatory bowel diseases (IBD) consisting of Crohn’s and ulcerative colitis are resultant of dysregulation of the immune system leading to intestinal inflammation and microbial dysbiosis. Numerous studies in recent years highlighted the pivotal role of gut microbiota and their metabolites in host physiological processes including in IBD. Urolithin A (UroA) is a microbial metabolite derived from polyphenolics (e.g., ellagitannins/ellagic acid) of pomegranate and berries. We also synthesized a potent structural analogue of UroA (UAS03) and tested their efficacies in preventing and treating colitis in pre-clinical models. Our studies showed that UroA/UAS03 significantly enhance gut barrier function in addition to blocking unwarranted inflammation. We demonstrate that UroA and UAS03 exert their barrier functions through activation of aryl hydrocarbon receptor (AhR)- nuclear factor erythroid 2–related factor 2 (Nrf2)-dependent pathways to upregulate epithelial tight junction proteins. In addition, treatment with these compounds attenuated colitis in pre-clinical models by remedying barrier dysfunction and blocking increased inflammatory mediators such as IL-6, TNF-α and IL-1β. UroA/UAS03 failed to induce tight junction proteins and protect against 2,4,6-Trinitrobenzenesulfonic acid (TNBS)-induced colitis in AhR−/− and Nrf2−/− mice suggesting an obligatory requirement of AhR and Nrf2 pathways for UroA/UAS03 mediated beneficial activities. Overall, the results highlight how microbial metabolites provide two-pronged beneficial activities at gut epithelium by enhancing barrier functions and reducing systemic and local inflammation to protect from colonic diseases.

Chemopreventive effects and associated mechanisms of withaferin A (WA) against intestinal and colon carcinogenesis remain unknown. We investigated the chemopreventive effect of WA on transgenic adenomatous polyposis coli (APCMin/+) mouse and chemically induced azoxymethane/dextran sodium sulfate (AOM/DSS) models of intestinal and colon carcinogenesis. Oral WA administration (4 and 3 mg/kg) inhibited tumor initiation and progression of intestinal polyps formation in APCMin/+ mice and colon carcinogenesis in the AOM/DSS mouse model. WA-administered mice showed a significant reduction in both number [duodenum, 33% (P > 0.05); jejunum, 32% (P < 0.025); ileum, 43% ( P < 0.001); and colon 59% (P < 0.01] and size of polyps in APCMin/+ mice compared with the respective controls. Similarly, tumor multiplicity was significantly reduced (P < 0.05) in the colon of WA-administered AOM/DSS mice. Pathological analysis showed reduced adenomas and tissue inflammation in WA-administered mouse models. Molecular studies suggested that WA inhibited the expression of inflammatory (interluekin-6, tumor necrosis factor-alpha and cyclooxygenase-2), pro-survival (pAKT, Notch1 and NF-κB) markers in APCMin/+ and AOM/DSS models. The results suggest that WA is a potent agent for preventing colon carcinogenesis and further investigation is required to show clinical utility of the agent.

Abstract We recently showed that two different ALDH+ and CD44+/CD24-/low breast cancer stem cells (BSCSs) exhibited stem cell characteristics that include self-renewal, extensive proliferation, the ability to form non-adherent spherical clusters, chemotherapy resistance and high Notch1 expression. We have identified a compound compound: 6-(3-methylbut-2-enyl) coumestrol (Pso) and treatment with Pso resulted in growth inhibition and an EMT phenotype in both BCSCs and BC cells. Oral Pso administration at physiologically achievable doses (25 mg/kg/BW) suppressed the growth of BCSCs and BC xenografts without toxicity. In the current studies, we identified several novel Pso-derived analogs that may be more potent than the parent compound. One such compound, 1-methoxyphaseollidin (1MP), obtained via three main functional group changes: (i) translocation of the isoprenyl moiety from the phenyl ring fused to the pyran ring (as in Pso) to the phenyl ring adjacent to the furan ring, (ii) removal of the carbonyl group from the pyran ring, and (iii) introduction of a methoxy group at the 1-position, inhibited Notch1 activity and growth of both BSCS and BC cells at nM concentration (IC50: 300nM), which is 100 times more potently than Pso in cell culture models. Molecular studies suggest that 1MP inhibits Notch signaling pathways (Hes1, Hey1 and Presenilin) in both BCSC and BC cells. Further, downregulation of AKT signaling (pAKT (S473), p65 and BCl-2 were seen in 1MP treated cells. Docking studies suggest that 1MP binds outside of the catalytic unit of γ-secretase and induces a conformational change, resulting in Notch1 inhibition in both BCSCs and BC cells. More importantly, administration of 1MP significantly inhibited the growth of BCSC and BC tumors without causing gastrointestinal toxicity in tumor-bearing mice. H&E staining suggests that 1MP treated tumors show infiltrate to margins are less as compared to vehicle treated mice’s. We believe targeting notch1 signaling and optimizing 1MP could be an effective therapeutic strategy for treating breast cancer. Note: This abstract was not presented at the meeting. Citation Format: Venkatesh Kolluru, Deeksha Pal, Becca Baby, Houda Alatassi, Arun Kumar Sharma, Murali Ankem, Chendil Damodaran. 1-Methoxyphaseollidin: Novel gamma secretase inhibitor targeting notch-1 signaling in breast cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2903. doi:10.1158/1538-7445.AM2017-2903

We have previously reported that high aldehyde dehydrogenase (ALDH) enzyme activity in breast cancer cells results in breast cancer stem cell (BCSC) properties by upregualting Notch-1 and epithelial mesenchymal markers. This results in chemoresistance in breast cancer. Here, we examined the functional and clinical significance of ALDH expression by measuring the ALDH levels in breast cancer tissues by immunohistochemistry. There was a significantly higher ALDH expression in higher grade breast cancer tumor tissues (Grade- II and III) versus normal breast tissues. Injection of BCSC (ALDH+ and CD44+ /CD22- ) cells resulted in aggressive tumor growth in athymic mice versus ALDH- cells. The ALDH+ and CD44+ /CD22- tumors grow rapidly and are larger than ALDH- tumors which were slow growing and smaller. Molecularly, ALDH+ tumors expressed higher expression of Notch-1 and EMT markers than ALDH- tumors. Oral administration of the naturally occurring Psoralidin (Pso, 25 mg/kg of body weight) significantly inhibited the growth in ALDH+ and ALDH- tumors as well. Psoralidin inhibited Notch-1 mediated EMT activation in ALDH+ and ALDH- tumors-this confirms our in vitro findings. Our results suggest that Notch-1 could be an attractive target and inhibition of Notch-1 by Psoralidin may prevent pathogenesis of breast cancer as well as metastasis. © 2016 Wiley Periodicals, Inc.