High serum levels of IL-6 correlate with poor outcome in breast cancer patients. However, no data are available on the relationship between IL-6 and mammary stem/progenitor cells, which may fuel the genesis of breast cancer in vivo. Herein, we address this issue in the MCF-7 breast cancer cell line and in primary human mammospheres (MS), multicellular structures enriched in stem/progenitor cells of the mammary gland. MS from node invasive breast carcinoma tissues expressed IL-6 mRNA at higher levels than did MS from matched nonneoplastic mammary glands. In addition, IL-6 mRNA was detected only in basal-like breast carcinoma tissues, an aggressive breast carcinoma variant showing stem cell features. IL-6 treatment triggered Notch-3-dependent upregulation of the Notch ligand Jagged-1 and promotion of MS and MCF-7-derived spheroid growth. Moreover, IL-6 induced Notch-3-dependent upregulation of the carbonic anhydrase IX gene and promoted a hypoxia-resistant/invasive phenotype in MCF-7 cells and MS. Finally, autocrine IL-6 signaling relied upon Notch-3 activity to sustain the aggressive features of MCF-7-derived hypoxia-selected cells. In conclusion, these data support the hypothesis that IL-6 induces malignant features in Notch-3-expressing stem/progenitor cells from human ductal breast carcinoma and normal mammary gland.

Cholangiocarcinoma (CCA) is a heterogeneous disease arising from a complex interaction between host‐specific genetic background and multiple risk factors. Globally, CCA incidence rates exhibit geographical variation, with much higher incidence in parts of the Eastern world compared to the West. These differences are likely to reflect differences in geographical risk factors as well as genetic determinants. Of note, over the past few decades, the incidence rates of CCA appear to change and subtypes of CCA appear to show distinct epidemiological trends. These trends need to be interpreted with caution given the issues of diagnosis, recording and coding of subtypes of CCA. Epidemiological evidences suggest that in general population some risk factors are less frequent but associated with a higher CCA risk, while others are more common but associated with a lower risk. Moreover, while some risk factors are shared by intrahepatic and both extrahepatic forms, others seem more specific for one of the two forms. Currently some pathological conditions have been clearly associated with CCA development, and other conditions are emerging; however, while their impact in increasing CCA risk as single etiological factors has been provided in many studies, less is known when two or more risk factors co‐occur in the same patient. Moreover, despite the advancements in the knowledge of CCA aetiology, in Western countries about 50% of cases are still diagnosed without any identifiable risk factor. It is therefore conceivable that other still undefined etiologic factors are responsible for the recent increase of CCA (especially iCCA) incidence worldwide.

The identification of target genes is a key step for assessing the role of aberrantly expressed microRNAs (miRNA) in human cancer and for the further development of miRNA-based gene therapy. MiR-122 is a liver-specific miRNA accounting for 70% of the total miRNA population. Its down-regulation is a common feature of both human and mouse hepatocellular carcinoma (HCC). We have previously shown that miR-122 can regulate the expression of cyclin G1, whose high levels have been reported in several human cancers. We evaluated the role of miR-122 and cyclin G1 expression in hepatocarcinogenesis and in response to treatment with doxorubicin and their relevance on survival and time to recurrence (TTR) of HCC patients. We proved that, by modulating cyclin G1, miR-122 influences p53 protein stability and transcriptional activity and reduces invasion capability of HCC-derived cell lines. In addition, in a therapeutic perspective, we assayed the effects of a restored miR-122 expression in triggering doxorubicin-induced apoptosis and we proved that miR-122, as well as cyclin G1 silencing, increases sensitivity to doxorubicin challenge. In patients resected for HCC, lower miR-122 levels were associated with a shorter TTR, whereas higher cyclin G1 expression was related to a lower survival, suggesting that miR-122 might represent an effective molecular target for HCC. Our findings establish a basis toward the development of combined chemo-and miRNA-based therapy for HCC treatment.

Common sites of breast cancer metastasis include the lung, liver, and bone, and of these secondary metastatic sites, estrogen receptor A (ERA)-positive breast cancer often favors bone. Within secondary organs, cancer cells would predictably encounter tissue-specific fibroblasts or their soluble factors, yet our understanding of how tissue-specific fibroblasts directly affect cancer cell growth rates and survival remains largely unknown. Therefore, we tested the hypothesis that mesenchymal fibroblasts isolated from common sites of breast cancer metastasis provide a more favorable microenvironment with respect to tumor growth rates. We found a direct correlation between the ability of breast, lung, and bone fibroblasts to enhance ERA-positive breast cancer cell growth and the level of soluble interleukin-6 (IL-6) produced by each organ-specific fibroblast, and fibroblast-mediated growth enhancement was inhibited by the removal or inhibition of IL-6. Interestingly, mice coinjected with MCF-7 breast tumor cells and senescent skin fibroblasts, which secrete IL-6, developed tumors, whereas mice coinjected with presenescent skin fibroblasts that produce little to no IL-6 failed to form xenograft tumors. We subsequently determined that IL-6 promoted growth and invasion of breast cancer cells through signal transducer and activator of transcription 3-dependent up-regulation of Notch-3, Jagged-1, and carbonic anhydrase IX. These data suggest that tissue-specific fibroblasts and the factors they produce can promote breast cancer disease progression and may represent attractive targets for development of new therapeutics. [Cancer Res 2008;68(21):9087-95]

Basal-like breast carcinoma is an aggressive form of breast cancer, characterized by the absence of oestrogen receptor and HER2 expression, the presence of cytokeratin 5 and epidermal growth factor receptor expression, and by the up-regulation of stem cell regulatory genes. We show here that tumour tissues expressing high levels of SLUG mRNA show a basal-like breast carcinoma phenotype and that such tumours also express high levels of stem cell-regulatory genes, ie CD133, Bmi1. Further, we show that stem/progenitor cells, isolated from ductal breast carcinoma and from normal mammary gland as mammospheres, express SLUG, CD133, and Bmi1 mRNA and show a phenotype similar to that of basal-like breast carcinoma. We also report that SLUG expression in tumour tissues correlates with that of the hypoxia survival gene carbonic anhydrase IX. In this regard, we report that the exposure of SLUG-negative/luminal-like MCF-7 cells to a hypoxic environment promotes the onset of the basal-like breast carcinoma phenotype, together with up-regulation of the SLUG gene, which in turn blunts oestrogen receptor-alpha and boosts carbonic anhydrase IX gene expression. Finally, we show that SLUG expression promotes the invasiveness of MCF-7 cells exposed to hypoxia and sustains the in vivo aggressiveness of hypoxia-selected, MCF-7-derived cells in xenografts. These data indicate that SLUG gene expression is part of a hypoxia-induced genetic programme which sets up a basal/stem cell-like, aggressive phenotype in breast cancer cells.

Extracellular and intracellular mediators of inflammation, such as Tumor Necrosis Factor alpha (TNFα) and NF-kappaB (NF-κB), play major roles in breast cancer pathogenesis, progression and relapse. SLUG, a mediator of the epithelial-mesenchymal transition process, is over-expressed in CD44 + /CD24 − tumor initiating breast cancer cells and in basal-like carcinoma, a subtype of aggressive breast cancer endowed with a stem cell-like gene expression profile. Cancer stem cells also over-express members of the pro-inflammatory NF-κB network, but their functional relationship with SLUG expression in breast cancer cells remains unclear. Here, we show that TNFα treatment of human breast cancer cells up-regulates SLUG with a dependency on canonical NF-κB/HIF1α signaling, which is strongly enhanced by p53 inactivation. Moreover, SLUG up-regulation engenders breast cancer cells with stem cell-like properties including enhanced expression of CD44 and Jagged-1 in conjunction with ERα down-regulation, growth as mammospheres and extracellular matrix invasiveness. Our results reveal a molecular mechanism whereby TNFα, a major proinflammatory cytokine, imparts breast cancer cells with stem cell-like features, which are connected to increased tumor aggressiveness.

Cholangiocarcinoma (CC) encompasses a group of related but distinct malignancies whose lack of a stereotyped genetic signature makes challenging the identification of genomic landscape and the development of effective targeted therapies.Accumulated evidences strongly suggest that the remarkable genetic heterogeneity of CC may be the result of a complex interplay among different causative factors, some shared by most human cancers while others typical of this malignancy.Currently, considerable efforts are ongoing worldwide for the genetic characterization of CC, also using advanced technologies such as next-generation sequencing (NGS). Undoubtedly this technology could offer an unique opportunity to broaden our understanding on CC molecular pathogenesis. Despite this great potential, however, the high complexity in terms of factors potentially contributing to genetic variability in CC calls for a more cautionary application of NGS to this malignancy, in order to avoid possible biases and criticisms in the identification of candidate actionable targets. This approach is further justified by the urgent need to develop effective targeted therapies in this disease.A multidisciplinary approach integrating genomic, functional and clinical studies is therefore mandatory to translate the results obtained by NGS into effective targeted therapies for this orphan disease.

Cholangiocarcinoma (CCA) is a rare, aggressive disease with poor overall survival. In advanced cases, surgery is often not possible or fails; in addition, there is a lack of effective and specific therapies. Multidisciplinary approaches and advanced technologies have improved the knowledge of CCA molecular pathogenesis, highlighting its extreme heterogeneity and high frequency of genetic and molecular aberrations. Effective preclinical models, therefore, should be based on a comparable level of complexity. In the past years, there has been a consistent increase in the number of available CCA models. The exploitation of even more complex CCA models is rising. Examples are the use of CRISPR/Cas9 or stabilized organoids for in vitro studies, as well as patient-derived xenografts or transgenic mouse models for in vivo applications. Here, we examine the available preclinical CCA models exploited to investigate: (i) carcinogenesis processes from initiation to progression; and (ii) tools for personalized therapy and innovative therapeutic approaches, including chemotherapy and immune/targeted therapies. For each model, we describe the potential applications, highlighting both its advantages and limits.