Cancer cells display phenotypic equilibrium between the stem-like and differentiated states during neoplastic homeostasis. The functional and mechanistic implications of this subpopulation plasticity remain largely unknown. Herein, it is demonstrated that the breast cancer stem cell (BCSC) secretome autonomously compresses the stem cell population. Co-implantation with BCSCs decreases the tumor-initiating capacity yet increases metastasis of accompanying cancer cells, wherein DKK1 is identified as a pivotal factor secreted by BCSCs for such functions. DKK1-promotes differentiation is indispensable for disseminated tumor cell metastatic outgrowth. In contrast, DKK1 inhibitors substantially relieve the metastatic burden by restraining metastatic cells in the dormant state. DKK1 increases the expression of SLC7A11 to protect metastasizing cancer cells from lipid peroxidation and ferroptosis. Combined treatment with a ferroptosis inducer and a DKK1 inhibitor exhibits synergistic effects in diminishing metastasis. Hence, this study deciphers the contribution of CSC-regulated phenotypic plasticity in metastatic colonization and provides therapeutic approaches to limit metastatic outgrowth.

Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer-related mortality with a dismal prognosis that has changed little over the past few decades. Further understanding of the molecular pathology of PDAC progression is urgently required in order to improve the prognosis of patients with PDAC. Herein, it was observed that trefoil factor 3 (TFF3) expression was elevated in PDAC, and was positively correlated with a worse overall patient survival outcome. Forced expression of TFF3 promoted oncogenic functions of PDAC cells in vitro including cell proliferation, survival, foci formation, cancer stem cell-like behavior and invasion, ex vivo colony growth in 3D-Matrigel, and xenograft growth in vivo. Depletion or pharmacological inhibition of TFF3 inhibited these same processes. RNA-Seq analysis and subsequent mechanistic analyses demonstrated that TFF3 increased the expression of various WNT ligands to mediate WNT pathway activation required for TFF3-stimulated PDAC progression. Combined pharmacological inhibition of TFF3 and WNT signaling significantly attenuated PDAC xenograft growth and potentiated the therapeutic efficacy of gemcitabine in both ex vivo and in vivo models. Hence, a mechanistic basis for combined inhibition of pathways enhancing PDAC progression is provided and suggests that inhibition of TFF3 may assist to ameliorate outcomes in PDAC.

Aberrant activation of the PI3K/AKT signaling axis along with the sustained phosphorylation of downstream BAD is associated with a poor outcome of TNBC. Herein, the phosphorylated to non-phosphorylated ratio of BAD, an effector of PI3K/AKT promoting cell survival, was observed to be correlated with worse clinicopathologic indicators of outcome, including higher grade, higher proliferative index and lymph node metastasis. The structural optimization of a previously reported inhibitor of BAD-Ser99 phosphorylation was therefore achieved to generate a small molecule inhibiting the phosphorylation of BAD at Ser99 with enhanced potency and improved oral bioavailability. The molecule 2-((4-(2,3-dichlorophenyl)piperazin-1-yl)(pyridin-3-yl)methyl) phenol (NCK) displayed no toxicity at supra-therapeutic doses and was therefore assessed for utility in TNBC. NCK promoted apoptosis and G0/G1 cell cycle arrest of TNBC cell lines in vitro, concordant with gene expression analyses, and reduced in vivo xenograft growth and metastatic burden, demonstrating efficacy as a single agent. Additionally, combinatorial oncology compound library screening demonstrated that NCK synergized with tyrosine kinase inhibitors (TKIs), specifically OSI-930 or Crizotinib in reducing cell viability and promoting apoptosis of TNBC cells. The synergistic effects of NCK and TKIs were also observed in vivo with complete regression of a percentage of TNBC cell line derived xenografts and prevention of metastatic spread. In patient-derived TNBC xenograft models, NCK prolonged survival times of host animals, and in combination with TKIs generated superior survival outcomes to single agent treatment. Hence, this study provides proof of concept to further develop rational and mechanistic based therapeutic strategies to ameliorate the outcome of TNBC.

Supplementation of piceatannol significantly alleviated CCl₄-induced hepatic fibrosis in mice.

Bisphenol A (BPA) is an environmental contaminant and can be detected in foodstuffs. Hence, investigating BPA metabolism in humans is crucial because certain BPA metabolites may exhibit similar or even greater be toxicity than does the parent compound. In this study, we used an advanced metabolomics-based data processing approach along with ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) to identify BPA metabolites in human liver enzyme incubation samples, and those metabolites were further detected in human excreta and water body samples in Taiwan. The first stage involved converting full-scan MS files from the incubation samples into feature information; this stage revealed 1056 and 2472 features with dose-response relationships in the BPA and isotopically labeled BPA incubation datasets, respectively. The second stage involved using stable isotope tracing to identify isotopic pairs from the two datasets; this stage revealed 190 isotopic pairs. An additional dose-response experiment was conducted to confirm that all these features with isotopic pairs also exhibited a dose-response relationship. To focus on the primary BPA metabolite features, we excluded those with low intensities (below 50,000). This left us with 86 features, which we then used for our analysis. To confirm these features as possible BPA metabolites, we compared the tandem MS (MS/MS) spectra between BPA and isotopically labeled BPA incubation samples. The results revealed 75 isotopic pairs with matching isotopically labeled MS/MS spectra. Among these identified features, one feature's m/z value matched to that of a previously reported BPA metabolite, and the other 74 features were novel. However, only 9 of them had proposed structures. We further investigated whether these features could be detected in humans or Taiwanese water bodies. Furthermore, 10 and 2 novel metabolites were identified in human urine and fecal samples, respectively; 17 novel metabolites were identified in the water samples. These findings indicate some of these novel metabolites are present not only in humans but also in various water bodies across Taiwan. These identified metabolites are phase I BPA metabolites, suggesting they may have toxic properties. Further research is warranted to investigate the structures of these newly discovered metabolites and assess their potential human health risks.