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International audience; Tumor recurrence is often attributed to cancer stem cells (CSCs). We previously demonstrated that down-regulation of Pregnane X Receptor (PXR) decreases the chemoresistance of CSCs and prevents colorectal cancer recurrence. Currently, no PXR inhibitor is usable in clinic. Here, we identify miR-148a as a targetable element upstream of PXR signaling in CSCs, which when over-expressed decreases PXR expression and impairs tumor relapse after chemotherapy in mouse tumor xenografts. We then develop a fluorescent reporter screen for miR-148a activators and identify the anti-helminthic drug niclosamide as an inducer of miR-148a expression. Consequently, niclosamide decreased PXR expression and CSC numbers in colorectal cancer patient-derived cell lines and synergized with chemotherapeutic agents to prevent CSC chemoresistance and tumor recurrence in vivo. Our study suggests that endogenous miRNA inducers is a viable strategy to down-regulate PXR and illuminates niclosamide as a neoadjuvant repurposing strategy to prevent tumor relapse in colon cancer.

Despite an increasing gain of knowledge regarding small extracellular vesicle (sEV) composition and functions in cell-cell communication, the mechanism behind their biogenesis remains unclear. Here, we revealed for the first time that the sEV biogenesis and release into the microenvironment are tightly connected with another important organelle: Lipid Droplets (LD). We have observed this correlation using different human cancer cell lines as well as patient-derived colorectal cancer stem cells (CR-CSCs). Our results showed that the use of external stimuli such as radiation, pH, hypoxia, or lipid interfering drugs, known to affect the LD content, had a similar effect in terms of sEV secretion. Additional validations were brought using multiple omics data, at the mRNA and protein levels. Altogether, the possibility to fine-tune sEV biogenesis by targeting LDs, could have a massive impact on the amount, the cargos and the properties of those sEVs, paving the way for new clinical perspectives.Significance Statement

Hedgehog–GLI (HH) signaling plays an essential role in embryogenesis and tissue homeostasis. Aberrant activation of the pathway through mutations or other mechanisms is involved in the development and progression of numerous types of cancer, including basal cell carcinoma, medulloblastoma, melanoma, breast, prostate, hepatocellular and pancreatic carcinomas. Activation of HH signaling sustains proliferation, suppresses cell death signals, enhances invasion and metastasis, deregulates cellular metabolism and promotes angiogenesis and tumor inflammation. Targeted inhibition of the HH pathway has therefore emerged as an attractive therapeutic strategy for the treatment of a wide range of cancers. Currently, the Smoothened (SMO) receptor and the downstream GLI transcriptional factors have been investigated for the development of targeted drugs. Recent studies have revealed that the HH signaling is also involved in tumor immune evasion and poor responses to cancer immunotherapy. Here we focus on the effects of HH signaling on the major cellular components of the adaptive and innate immune systems, and we present recent discoveries elucidating how the immunosuppressive function of the HH pathway is engaged by cancer cells to prevent immune surveillance. In addition, we discuss the future prospect of therapeutic options combining the HH pathway and immune checkpoint inhibitors.

Conventional stimulated Raman scattering (SRS) microscopes perform spectral acquisitions probing one single Raman shift (wavenumber) at a time. A multiplexed approach, however, would allow to perform faster spectral acquisitions, either measuring several wavenumbers in parallel or using reconstruction techniques that increase the signal to noise ratio (SNR). While the first approach often requires the use of complex technical solutions, the latter can be implemented with minor changes to an already existing broadband setup.

We present a novel configuration for high spectral resolution multiplexing acquisition based on the Hadamard transform in stimulated Raman scattering (SRS) microscopy. The broadband tunable output of a dual-beam femtosecond laser is filtered by a fast, narrowband, and multi-channel acousto-optic tunable filter (AOTF). By turning on and off different subsets of its 8 independent channels, the AOTF generates the spectral masks given by the Hadamard matrix. We demonstrate a seamless and automated operation in the Raman fingerprint and CH-stretch regions. In the presence of additive noise, the spectral measurements using the multiplexed method show the same signal-to-noise ratio of conventional single-wavenumber acquisitions performed with 4 times longer integration time.

We present a novel design for a Stimulated Raman Scattering (SRS) microscope based on a dual beam femtosecond laser in combination with spectral shaping through a fast and narrowband Acousto Optical Tunable Filter. This configuration allows the measurement of broad SRS spectra, all the way from fingerprint region to CH stretch region without any modification of the optical setup. High spectral resolution over a broad spectral region allows label-free quantitative imaging of biological samples. We will show the application of our SRS system to a quantitative study of lipid droplets in colon Cancer Stem Cells.

Colorectal cancer is the fourth most common cause of cancer-related death. Although many advances in the treatment of this disease have been made, a large number of patients develop metastasis and resistance to current therapies. The current evidence indicates that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) have crucial roles in colorectal carcinogenesis and metastasis. It is also very important to understand the mechanisms that allow the survival of CSCs, such as metabolic reprogramming, which permits them to obtain specific properties or the activation of alternative signaling pathways in response to first-line therapies. In this review, we discuss the failure of conventional therapies for colorectal cancer and provide a brief analysis of new therapeutic strategies for targeting non-responsive CSC. We highlight the use of combination therapies, such as horizontal or vertical targeting, as the most efficient strategy for eradicating these subpopulations of cancer cells.

Basal-like breast cancer is an aggressive tumor subtype with a poor response to conventional therapies. Tumor formation and relapse are sustained by a cell subset of Breast Cancer Stem Cells (BrCSCs). Here we show that miR-100 inhibits maintenance and expansion of BrCSCs in basal-like cancer through Polo-like kinase1 (Plk1) down-regulation. Moreover, miR-100 favors BrCSC differentiation, converting a basal like phenotype into luminal. It induces the expression of a functional estrogen receptor (ER) and renders basal-like BrCSCs responsive to hormonal therapy. The key role played by miR-100 in breast cancer free-survival is confirmed by the analysis of a cohort of patients' tumors, which shows that low expression of miR-100 is a negative prognostic factor and is associated with gene signatures of high grade undifferentiated tumors. Our findings indicate a new possible therapeutic strategy, which could make aggressive breast cancers responsive to standard treatments.

Background The use of stem cells, including mesenchymal stem cells (MSCs), for regenerative medicine is gaining interest for the clinical benefits so far obtained in patients. This study investigates the use of adipose autologous tissue in combination with platelet-rich plasma (PRP) to improve the clinical outcome of patients affected by systemic sclerosis (SSc). Methods Adipose-derived mesenchymal stem cells (AD-MSCs) and PRPs were purified from healthy donors and SSc patients. The multilineage differentiation potential of AD-MSCs and their genotypic–phenotypic features were investigated. A cytokine production profile was evaluated on AD-MSCs and PRPs from both healthy subjects and SSc patients. The adipose tissue-derived cell fraction, the so-called stromal vascular fraction (SVF), was coinjected with PRP in the perioral area of SSc patients. Results Histopathological and phenotypical analysis of adipose tissue from SSc patients revealed a disorganization of its distinct architecture coupled with an altered cell composition. Although AD-MSCs derived from SSc patients showed high multipotency, they failed to sustain a terminally differentiated progeny. Furthermore, SVFs derived from SSc patients differed from healthy donors in their MSC-like traits coupled with an aberrant cytokine production profile. Finally, the administration of PRP in combination with autologous SVF improved buccal’s rhyme, skin elasticity and vascularization for all of the SSc patients enrolled in this study. Conclusions This innovative regenerative therapy could be exploited for the treatment of chronic connective tissue diseases, including SSc. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0690-3) contains supplementary material, which is available to authorized users.

Background: Despite the advent of successful treatment of localized malignancies, metastatic cancer still lacks efficacious therapeutic approaches, including breast cancer. It is now well established that within malignant tumors Cancer Stem Cells (CSCs) constitute a unique cell subset that fuel and succeed at tumor growth and metastases formation. Tumor microenvironment sustains CSCs characteristics, making the molecular mechanisms driving tumor progression and recurrence more complex and difficult to elucidate. Furthermore, the interaction that occurs between CSCs and the nearby stroma has proven to enhance the aggressive behavior of several carcinomas through the secretion of microenvironmental cytokines. In this context, IL-4 has already been described to promote survival of cancer cells through the up-regulation of several anti-apoptotic factors. However, still little is known about its role in promoting breast cancer progression. Results: Here we show for the first time that autocrine and paracrine production of IL-4 regulates breast CSCs (BCSCs) features, including cell proliferation, motility and cytoskeletal organization via RAS/MAPK pathway. Interestingly, relief from IL-4 impaired BCSCs proliferation, colony forming efficiency and in vivo tumor formation, while it fostered the expression of the dual specificity phosphatase-4 (DUSP4) in triple-negative basal-like BCSCs, leading to the decrease of CD44+/CD24- population. DUSP4 is commonly deficient in the most aggressive breast cancers, such as the basal-like subtype. Likewise, we observed that the enforced expression of DUSP4 increases the CD24+ compartment in basal-like BCSCs, determining also a dramatic decrease of their proliferation, colony forming efficiency, invasiveness and metastases formation. Contrarily, in luminal-like BCSCs, DUSP4 suppression favors BCSCs cell traits, including their tumorigenic and metastagenic properties. Methods: Patient-derived BCSCs were obtained by digestion of breast cancer tissues and plated in serum-free media with bFGF and EGF. DUSP4 were inserted into the p-Lenti expression vector. Stable DUSP4 knockdown was produced by lentiviral transduction of the pGFP-C vector. IL-4 function was impaired by using a high affinity IL-4Rα antagonist. To assess tumorigenicity and metastases formation, BCSCs were suspended in matrigel and injected either orthotopically or intra caudal in NOD/SCID mice. Conclusions: These findings will shed light on the molecular basis of cancer progression and on the complex crosstalk occurring between tumor and its microenvironment. The identification of tumor-related molecular events, such as the IL-4 activated signaling, might be clinically exploited as therapeutic targets in the adjuvant setting and synergize the effect of conventional chemotherapy in patients affected by breast cancers with limited therapeutic options, such as triple-negative breast cancers. Citation Format: Alice Turdo, Miriam Gaggianesi, Tiziana Apuzzo, Antonina Benfante, Aurora Chinnici, Alessandro Giammona, Simone Di Franco, Giorgio Stassi, Matilde Todaro. Autocrine and paracrine IL-4 maintains breast cancer stem cells traits via RAS/MAPK/DUSP pathway. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3311.

// Annalisa Petrelli 1,* , Rosachiara Carollo 2,* , Marilisa Cargnelutti 1 , Flora Iovino 2 , Maurizio Callari 3 , Daniela Cimino 4 , Matilde Todaro 2 , Laura Rosa Mangiapane 2 , Alessandro Giammona 2 , Adriana Cordova 2 , Filippo Montemurro 1 , Daniela Taverna 4 , Maria Grazia Daidone 3 , Giorgio Stassi 2,* and Silvia Giordano 1,* 1 University of Torino School of Medicine, Candiolo Cancer Institute-FPO, IRCCS, Str. Provinciale, Candiolo, Torino, Italy 2 Department of Surgical and Oncological Sciences, Cellular and Molecular Pathophysiology Laboratory, University of Palermo, Palermo, Italy 3 Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy 4 Molecular Biotechnology Center (MBC), Department of Oncological Sciences, Center for Molecular Systems Biology, Via Nizza, University of Torino, Torino, Italy * These authors contributed equally to this work Correspondence: Silvia Giordano, email: // Giorgio Stassi, email: // Annalisa Petrelli, email: // Keywords : Breast cancer, basal-like, differentiation, miR-100 Received : September 30, 2014 Accepted : December 10, 2014 Published : December 11, 2014 Abstract Basal-like breast cancer is an aggressive tumor subtype with a poor response to conventional therapies. Tumor formation and relapse are sustained by a cell subset of Breast Cancer Stem Cells (BrCSCs). Here we show that miR-100 inhibits maintenance and expansion of BrCSCs in basal-like cancer through Polo-like kinase1 (Plk1) down-regulation. Moreover, miR-100 favors BrCSC differentiation, converting a basal like phenotype into luminal. It induces the expression of a functional estrogen receptor (ER) and renders basal-like BrCSCs responsive to hormonal therapy. The key role played by miR-100 in breast cancer free-survival is confirmed by the analysis of a cohort of patients’ tumors, which shows that low expression of miR-100 is a negative prognostic factor and is associated with gene signatures of high grade undifferentiated tumors. Our findings indicate a new possible therapeutic strategy, which could make aggressive breast cancers responsive to standard treatments.