Mesenchymal stromal cells (MSCs) are characterized by an extraordinary capacity to modulate the phenotype and functional properties of various immune cells that play an essential role in the pathogenesis of inflammatory disorders. Thus, MSCs efficiently impair the phagocytic and antigen-presenting capacity of monocytes/macrophages and promote the expression of immunosuppressive molecules such as interleukin (IL)-10 and programmed cell death 1 ligand 1 by these cells. They also effectively inhibit the maturation of dendritic cells and their ability to produce proinflammatory cytokines and to stimulate potent T-cell responses. Furthermore, MSCs inhibit the generation and proinflammatory properties of CD4+ T helper (Th)1 and Th17 cells, while they promote the proliferation of regulatory T cells and their inhibitory capabilities. MSCs also impair the expansion, cytokine secretion, and cytotoxic activity of proinflammatory CD8+ T cells. Moreover, MSCs inhibit the differentiation, proliferation, and antibody secretion of B cells, and foster the generation of IL-10-producing regulatory B cells. Various cell membrane-associated and soluble molecules essentially contribute to these MSC-mediated effects on important cellular components of innate and adaptive immunity. Due to their immunosuppressive properties, MSCs have emerged as promising tools for the treatment of inflammatory disorders such as acute graft-versus-host disease, graft rejection in patients undergoing organ/cell transplantation, and autoimmune diseases.

Homologous recombination (HR) DNA repair deficient (HRD) breast cancers have been shown to be sensitive to DNA repair targeted therapies. Burgeoning evidence suggests that sporadic breast cancers, lacking germline BRCA1/BRCA2 mutations, may also be HRD. We developed a functional ex-vivo RAD51-based test to identify HRD primary breast cancers. An integrated approach examining methylation, gene expression and whole-exome sequencing was employed to ascertain the etiology of HRD. Functional HRD breast cancers displayed genomic features of lack of competent HR, including large-scale state transitions and specific mutational signatures. Somatic and/or germline genetic alterations resulting in bi-allelic loss-of-function of HR genes underpinned functional HRD in 89% of cases, and were observed in only one of the 15 HR-proficient samples tested. These findings indicate the importance of a comprehensive genetic assessment of bi-allelic alterations in the HR pathway to deliver a precision medicine-based approach to select patients for therapies targeting tumor-specific DNA repair defects.

Lobular carcinoma (LCIS) is a preinvasive lesion of the breast. We sought to define its genomic landscape, whether intralesion genetic heterogeneity is present in LCIS, and the clonal relatedness between LCIS and invasive breast cancers. We reanalyzed whole-exome sequencing (WES) data and performed a targeted amplicon sequencing validation of mutations identified in 43 LCIS and 27 synchronous more clinically advanced lesions from 24 patients [9 ductal carcinomas (DCIS), 13 invasive lobular carcinomas (ILC), and 5 invasive ductal carcinomas (IDC)]. Somatic genetic alterations, mutational signatures, clonal composition, and phylogenetic trees were defined using validated computational methods. WES of 43 LCIS lesions revealed a genomic profile similar to that previously reported for ILCs, with mutations present in 81% of the lesions. Forty-two percent (18/43) of LCIS were found to be clonally related to synchronous DCIS and/or ILCs, with clonal evolutionary patterns indicative of clonal selection and/or parallel/branched progression. Intralesion genetic heterogeneity was higher among LCIS clonally related to DCIS/ILC than in those nonclonally related to DCIS/ILC. A shift from aging to APOBEC-related mutational processes was observed in the progression from LCIS to DCIS and/or ILC in a subset of cases. Our findings support the contention that LCIS has a repertoire of somatic genetic alterations similar to that of ILCs, and likely constitutes a nonobligate precursor of breast cancer. Intralesion genetic heterogeneity is observed in LCIS and should be considered in studies aiming to develop biomarkers of progression from LCIS to more advanced lesions.

Purpose Lobular carcinoma in situ (LCIS) has been proposed as a non-obligate precursor of invasive lobular carcinoma (ILC). Here we sought to define the repertoire of somatic genetic alterations in pure LCIS and in synchronous LCIS and ILC using targeted massively parallel sequencing. Methods DNA samples extracted from microdissected LCIS, ILC and matched normal breast tissue or peripheral blood from 30 patients were subjected to massively parallel sequencing targeting all exons of 273 genes, including the genes most frequently mutated in breast cancer and DNA repair-related genes. Single nucleotide variants and insertions and deletions were identified using state-of-the-art bioinformatics approaches. Results The constellation of somatic mutations found in LCIS (n=34) and ILC (n=21) were similar, with the most frequently mutated genes being CDH1 (56% and 66%, respectively), PIK3CA (41% and 52%, respectively) and CBFB (12% and 19%, respectively). Among 19 LCIS and ILC synchronous pairs, 14 (74%) had at least one identical mutation in common, including identical PIK3CA and CDH1 mutations. Paired analysis of independent foci of LCIS from 3 breasts revealed at least one common mutation in each of the 3 pairs (CDH1, PIK3CA, CBFB and PKHD1L1). Conclusion LCIS and ILC have a similar repertoire of somatic mutations, with PIK3CA and CDH1 being the most frequently mutated genes. The presence of identical mutations between LCIS-LCIS and LCIS-ILC pairs demonstrates that LCIS is a clonal neoplastic lesion, and provides additional evidence that at least some LCIS are non-obligate precursors of ILC.

BackgroundRecent evidence suggests that lobular carcinoma in situ (LCIS) can be a clonal precursor of invasive breast cancers of both the ductal and lobular phenotypes. We sought to confirm these findings with an extensive study of fresh frozen breast specimens from women undergoing mastectomy.MethodsPatients with a history of LCIS presenting for therapeutic mastectomy were identified prospectively. Frozen tissue blocks were collected, screened for lesions of interest, and subjected to microdissection and DNA extraction. Copy number profiling, whole-exome sequencing, or both were performed. Clonal relatedness was assessed using specialized statistical techniques developed for this purpose.ResultsAfter exclusions for genotyping failure, a total of 84 lesions from 30 patients were evaluated successfully. Strong evidence of clonal relatedness was observed between an LCIS lesion and the invasive cancer for the preponderance of cases with lobular carcinoma. Anatomically distinct in situ lesions of both ductal and lobular histology were also shown to be frequently clonally related.ConclusionsThese data derived from women with LCIS with or without invasive cancer confirm that LCIS is commonly the clonal precursor of invasive lobular carcinoma and that distinct foci of LCIS frequently share a clonal origin, as do foci of LCIS and ductal carcinoma in situ.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-016-0727-z) contains supplementary material, which is available to authorized users.

Reducing the complex extracellular matrices (ECM) to chemically defined polymer networks represents an attractive avenue for understanding and recapitulating the biology of the ECM. However, while lipids are also important components of ECM, it remains challenging to investigate lipids as a modular functionality in synthetic biomaterials, especially in a self-assembled network. In this study, in order to establish a modular amphiphilic system, lipid-modifications are introduced into a noncovalent hydrogel system cross-linked by peptide–polysaccharide interaction through conjugating fatty acids of different lengths to a peptide. The amphiphilic matrices can interact with hydrophobic drugs, thus enhance their loading efficiency and result in sustainable release. The physical hydrogel system can be used for encapsulating cells, while embedded mesenchymal stromal cells exhibit high viability and retain immunoregulatory activity. In addition, the material can also be used for gel-in-gel injection to model drug partitioning in 3D, as well as controlled fast gel degradation under an extremely mild condition using human serum albumin (HSA). This self-assembling modular system can provide a versatile toolbox to tailor synthetic polymers for engineering 3D models to study bioactive molecules, such as hydrophobic hormones and drugs as well as to develop injectable therapeutic materials.

Purpose HSP90, a viable target for cancer treatment, mediates the maturation and stabilization of client oncoproteins. HSP90i are potentially active in a variety of tumors, but therapeutic benefit is confirmed in only a small subset. We explored potential biomarkers across multiple studies of HSP90i in advanced solid tumors. Methods Archived tumor specimens from patients treated with HSP90i on 7 different phase I/II trials at MSKCC were identified. Tumor tissue was tested by IHC: ER, PR and AR: ≥1% positive and <1% negative; HSP90 and HSP70: 0, 1+ negative and 2+, 3+ positive; PTEN: 0 negative, 1 reduced and 2 positive; HER2: 0, 1+ negative, 2+ equivocal, 3+ positive; EGFR: 0 negative and 1+, 2+, 3+ positive. The expression of the biomarker panel was correlated with clinical benefit (CB) (defined by ORR or CB by “8 week” scan) using Fisher's exact test. Results Adequate tissue was available for 51/158 patients (32%), including 10 different solid tumors. Of these, 71% (36/51) and 51 % (26/51) patients met the criteria to assess CB by best ORR or by “8 week scan” assessment respectively. Breast was the most frequent tumor. Mean duration of HSP90i therapy was 55 days (range, 16-411). There were 16 responses (4 PR; 12 SD); 13/16 responses strongly correlated with HER2+ status (p = 0.001). Conclusion Our findings suggest HER2 as a sensitive client and perhaps the only effective biomarker for sensitivity to these HSP90i.

diseases for which no therapies currently exist including graft-versus-host disease, [1,2] autoimmune diseases, [3] liver diseases, [4] orthopedic injuries, [5] cardiovascular diseases, [6] and cancer. [7] But despite high interest and a large number of clinical trials, only three hMSC-based therapies have been clinically approved yet. This might be largely due to the fact that their medical application still faces many challenges including heterogeneity in therapeutic targets, routes of delivery, range of doses, and manufacturing protocols. [8] With minimal effective doses ranging from 70 to 900 million cells per patient extensive ex vivo expansion and large-scale production are required. [9] Furthermore, the therapeutic efficacy and proliferation capacity of hMSCs decline during aging and passaging, and thus optimal growth conditions in vitro are urgently needed to produce adequate numbers of high-quality cells for clinical use. [10,11] hMSCs have been isolated from a wide range of adult and perinatal tissues and are advantageous to induced pluripotent and embryonic stem cells by not bearing the risk of tumorigenesis and their easy applicability. [12,13] They are a heterogeneous population of tissue-specific stem/progenitor cells that possess the ability to recreate the tissue from which they are isolated. [14] The self-renewal and differentiation potential of hMSCs are influenced by not only their tissue of origin but also donor age, genetics, exposure to environmental stress, and passaging in vitro. [15,16] Since their morphology can easily be mistaken for fibroblasts, the International Society for Cellular Therapy defined minimal criteria for hMSCs in vitro: 1) adherent growth in plastic culture dishes, 2) differentiation capacity into adipocytes, osteocytes, and chondrocytes, and 3) expression of CD73, CD105, and CD90 in at least 95% of the cell population and absence of the hematopoietic markers CD45, CD34, CD11b, or CD14. [17] hMSCs express also other cell surface molecules, for example, CD146, intercellular adhesion molecule (ICAM), CD271, Nestin, and leptin receptor that define them as multipotent tissue-specific stem/progenitor cells. The most frequently used source of hMSCs for clinical trials is bone marrow, from which cells can be isolated using Ficoll density gradient centrifugation. The subsequent ex vivo expansion is facilitated by nutrients, growth factors, and extracellular matrix (ECM) proteins present in the undefined soluble component of Human mesenchymal stromal cells (hMSCs) have enormous potential for the treatment of various inflammatory and degenerative diseases. Their manufacturing for cell-based therapies requires extensive ex vivo expansion and optimal growth conditions. To support cell adhesion, spreading, and growth in serum-free culture conditions, the applied plasticware needs to be functionalized with essential biochemical cues. By employing a recently developed screening tool, a chemically defined functional matrix composed of dextran sulfate and a bone-related extracellular ma...