Rosa Artells

Overlapping expression of microRNAs in human embryonic colon and colorectal cancer.

MicroRNAs (miRNAs) are essential for regulating cell differentiation and maintaining the pluripotent state of stem cells. Although dysregulation of specific miRNAs has been associated with certain types of cancer, to date no evidence has linked miRNA expression in embryonic and tumor tissues. We assessed the expression of mature miRNAs in human embryonic colon tissue, and in colorectal cancer and paired normal colon tissue. Overlapping miRNA expression was detected between embryonic colonic mucosa and colorectal cancer. We have found that the miR-17-92 cluster and its target, E2F1, exhibit a similar pattern of expression in human colon development and colonic carcinogenesis, regulating cell proliferation in both cases. In situ hybridization confirmed the high level of expression of miR-17-5p in the crypt progenitor compartment. We conclude that miRNA pathways play a major role in both embryonic development and neoplastic transformation of the colonic epithelium.

A Single-Nucleotide Polymorphism in the Aromatase Gene Is Associated with the Efficacy of the Aromatase Inhibitor Letrozole in Advanced Breast Carcinoma

Purpose: To evaluate the efficacy of treatment with the aromatase inhibitor letrozole in breast cancer patients segregated with respect to DNA polymorphisms of the aromatase gene CYP19. Patients and Methods: Postmenopausal patients (n = 67) with hormone receptor–positive metastatic breast cancer were treated with the aromatase inhibitor letrozole. PCR allelic discrimination was used to examine three single-nucleotide polymorphisms (SNP) in DNA obtained from breast carcinoma tissue. Two SNPs analyzed (rs10046 and rs4646) were located in the 3′ untranslated region and one (rs727479) was in the intron of the aromatase CYP19 gene. The primary end point of treatment efficacy was time to progression (TTP). Results: Median age was 62 years and median number of metastatic sites was 2. Observed allelic SNP frequencies were rs10046, 71%; rs4646, 46%; and rs727479, 63%. Of the 67 patients, 65 were evaluable for efficacy. Median TTP was 12.1 months. We observed no relationship between TTP and the rs10046 or rs727479 variants. In contrast, we found that TTP was significantly improved in patients with the rs4646 variant, compared with the wild-type gene (17.2 versus 6.4 months; P = 0.02). Conclusion: In patients with hormone receptor–positive metastatic breast cancer treated with the aromatase inhibitor letrozole, the presence of a SNP in the 3′ untranslated region of the CYP19 aromatase gene is associated with improved treatment efficacy. Testing for the CYP19 rs4646 SNP as a predictive tool for breast cancer patients on antiaromatase therapy deserves prospective evaluation.

Single Nucleotide Polymorphisms in Nucleotide Excision Repair Genes XPA, XPD, XPG and ERCC1 in Advanced Colorectal Cancer Patients Treated with First-Line Oxaliplatin/Fluoropyrimidine

Background/Aims: Oxaliplatin damages the DNA, leading to apoptosis. XPA, XPD, ERCC1 and XPG genes are involved in DNA repair, and single nucleotide polymorphisms (SNPs) in these genes can influence the efficacy of oxaliplatin. We examined SNPs in these genes and correlated the results with time to progression (TTP), overall survival and response to oxaliplatin in 42 advanced colorectal cancer patients (CRC) treated with first-line oxaliplatin/fluoropyrimidine. Methods: DNA was obtained from peripheral blood cells, and the allelic discrimination assay was used to analyze the XPA 5′UTR T/C, XPD Lys751Gln, ERCC1 Lys259Thr and XPG, C/T. Results: Patients with XPG C/C genotype had a longer survival (p = 0.001) and TTP (p = 0.009) than patients with XPG C/T or T/T genotypes, and patients with both XPG C/C and XPA T/C or C/C genotypes had a longer survival (p = 0.0001) and TTP (p = 0.0001) than patients with other genotypes. XPG (CC) combined with XPA (TC/CC) genotypes showed an independent role for TTP (relative risk, RR = 6.38; p = 0.0001) and survival (RR = 34; p = 0.0005). Conclusion: Polymorphism in XPG combined with XPA may be an important prognosticator of clinical outcome following oxaliplatin/ fluoropyrimidine chemotherapy. Further studies in larger patient cohorts are warranted to confirm their role in CRC.

Tumour CD133 mRNA expression and clinical outcome in surgically resected colorectal cancer patients

BACKGROUND Human prominin-1 (CD133) is a novel pentaspan membrane protein which was originally classified as a marker of primitive haematopoietic and neural stem cells. Cancer stem cells have been isolated and expanded from leukaemia and several solid tumours, and have been associated with metastasis, chemoresistance and relapse. CD133 is recognised as a stem cell marker and is capable of identifying a tumour-initiating subpopulation in brain, colon, melanoma and other solid tumours. METHODS We assessed CD133 mRNA expression levels by RT-QPCR in tumour and matched normal tissue from 64 stages I-III colorectal cancer (CRC) patients and correlated tumour CD133 levels with clinicopathological characteristics and clinical outcome. RESULTS In four patients, CD133 mRNA was not expressed in tumour or in normal tissue. In the remaining 60 patients, expression levels were higher in tumour than in normal tissue (p=0.001). Higher levels of CD133 expression were associated with shorter relapse-free interval (RFI) (p=0.004) and overall survival (OS) (p<0.0001). In the multivariate analyses, CD133 levels emerged as a prognostic marker for RFI and OS. CONCLUSIONS We have observed longer RFI and OS in patients with lower levels of CD133, regardless of adjuvant treatment and other clinical characteristics. If these findings are confirmed in larger prospective studies, CD133 assessment may prove useful for new diagnostic and therapeutic procedures for CRC patients.

Lestaurtinib Inhibition of the JAK/STAT Signaling Pathway in Hodgkin Lymphoma Inhibits Proliferation and Induces Apoptosis

Standard cytotoxic chemotherapy for Hodgkin Lymphoma (HL) has changed little in 30 years; the treatment for patients with relapsed or refractory disease remains challenging and novel agents are under development. JAK/STAT constitutive activation plays an important role in the pathogenesis of HL. Lestaurtinib is an orally bioavailable multikinase inhibitor that has recently been shown to inhibit JAK2 in myeloproliferative disorders. The potential role of Lestaurtinib in HL therapy is unknown. We have analyzed the effect of Lestaurtinib treatment in five HL cell lines from refractory patients, L-428, L-1236, L-540, HDML-2 and HD-MY-Z. At 48 h, a dose-dependent cell growth inhibition (23%–66% at 300 nM) and apoptotic increment (10%–64% at 300 nM) were observed. Moreover, Lestaurtinib inhibited JAK2, STAT5 and STAT3 phosphorylation and reduced the mRNA expression of its downstream antiapoptotic target Bcl-xL. In addition, we have analyzed the effect of Lestaurtinib treatment in lymph nodes from four classic HL patients. We observed a decrease in cell viability at 24 hours of treatment in three patients (mean decrease of 27% at 300 nM). Our findings provide, for the first time, a molecular rationale for testing JAK2 inhibitors, specifically Lestaurtinib, in HL patients.

Role of miR-200 family members in survival of colorectal cancer patients treated with fluoropyrimidines

Surgery is the standard treatment for colorectal cancer (CRC), and adjuvant chemotherapy has been shown to be effective in stage III but less so in stage II. We have analyzed the expression of the miR‐200 family in tissue samples from resected CRC patients and correlated our findings with survival to adjuvant treatment with fluoropyrimidines.

Common variants in NLRP2 and NLRP3 genes are strong prognostic factors for the outcome of HLA-identical sibling allogeneic stem cell transplantation

The inflammasomes are macromolecular cytosolic complexes involved in the production of interleukin-1beta (IL-1beta) and IL-18 in response to several pathogen-derived stimuli. Such interleukins have been implicated in the origin of severe allogeneic stem cell transplant (allo-SCT) complications. We analyzed the relationship between the interindividual variability in inflammasome protein-encoding genes in donors and patients and clinical outcome after allo-SCT. Fourteen common genetic variants in 5 genes of the inflammasome, namely, NLRP1, NLRP2, NLRP3, CARD8, and CASP5, were genotyped in 133 human leukocyte antigen-identical sibling pairs undergoing allo-SCT. In the multivariate analysis, donor variants in NLRP2 and NLRP3 were the most important prognostic factors for the clinical outcome after allo-SCT. Thus, donor TT genotype at rs10925027 in NLRP3 was associated with disease relapse (odds ratio (OR) = 6.3, P = 1 x 10(-7)), and donor GG genotype at rs1043684 in NLRP2 was associated with nonrelapse mortality (OR = 4.4, P = 6 x 10(-4)) and overall survival (OR = 3.1, P = .001). In addition, patient AA genotype at rs5862 in NLRP1 was associated with nonrelapse mortality (OR = 2.8, P = .005) and overall survival (OR = 2.0, P = .009). These results suggest that inflammasome genetic variants are important prognostic factors for the outcome of allo-SCT. If validated in larger studies, including unrelated allo-SCT, NLRPs genotype would become an important factor in donor selection.

Single nucleotide polymorphisms associated with non-contact soft tissue injuries in elite professional soccer players: influence on degree of injury and recovery time

BackgroundThe biological mechanisms involved in non-contact musculoskeletal soft tissue injuries (NCMSTI) are poorly understood. Genetic risk factors may be associated with susceptibility to injuries, and may exert marked influence on recovery times.MethodsData on type and degree of injury and recovery time were collected in 73 male professional soccer players (43 White, 11 Black Africans and 19 Hispanics) who suffered total of 242 injuries (203 muscle, 24 ligament, and 15 tendon injuries). One single nucleotide polymorphism (SNPs) in the following genes were analyzed: Elastin (ELN); Titin (TTN); SRY-related HMG-box (SOX15); Insulin-like growth factor 2 (IGF2); Chemokine, CC motif, ligand 2 (CCL2); Collagen type 1 alpha 1(COL1A1); Collagen type 5 alpha 1 (COL5A1), and Tenascin C (TNC).ResultsThere was evidence of a statistically significant association between the degree of injury and the IGF2 genotype (P = 0.034). In addition, there was evidence of a statistically significant association between the degree of muscle injury and CCL2 (P = 0.026) Finally, there was evidence of a statistically significant association between ELN and degree of injury (p = 0.009) and recovery time (P = 0.043). There was no evidence of a statistically significant association between any of the genes studied and degree of injury or recovery time for tendon injuries.ConclusionSNPs in the IGF2, CCL2, and ELN genes may be associated to the degree and recovery time of NCMSTI.

Ultrastructural and Immunohistochemical Analysis of Intestinal Myofibroblasts During the Early Organogenesis of the Human Small Intestine

Intestinal myofibroblasts (IMFs), also known as pericryptal fibroblasts, are found at the basement membrane of the intestinal epithelium. They are characterized by well‐developed endoplasmic reticulum, cytoplasmic fibers, and fibrous extensions called fibronexi. IMFs have structural features in common both with fibroblasts and smooth cells. Vimentin, desmin, and α‐smooth‐muscle actin (α‐SM) are markers commonly used to discriminate between IMFs and smooth muscle cells. Immunohistochemical studies have shown that, when α‐SM and vimentin are positive in both IMFs and smooth muscle cells, desmin is negative in IMFs but positive in smooth muscle cells. In the adult intestine, IMFs play an important role in various functions, especially in tissue repair and scar formation during wound healing. In the embryonic intestine, however, wound healing does not occur, and to date, no studies have investigated the first appearance and subsequent evolution of IMFs. In this study, we have examined the human small intestine in embryos at 7, 9, and 11 weeks of development by ultrastructural and immunohistochemical analysis to shed light on the formation of IMFs during these early phases of organogenesis. At 7 weeks, the embryonic mesenchymal cells are similar to proto‐myofibroblasts and may be the precursors of the IMFs detected at 9 weeks and more abundantly at 11 weeks by immunohistochemistry. These IMFs seem to mediate information flow between the epithelium and the mesenchyme and thus contribute to the development of the small intestine. Anat Rec, 2011.

Expression of Myosin Heavy Chain Isoforms in the Supraspinatus Muscle of Different Primate Species: Implications for the Study of the Adaptation of Primate Shoulder Muscles to Different Locomotor Modes

The supraspinatus muscle is a key component of the soft tissues of the shoulder. In pronograde primates, its main function, in combination with the other rotator cuff muscles (subscapularis, infraspinatus, and teres minor), is to stabilize the glenohumeral joint, whereas in orthograde primates it functions together with the deltoid, to elevate the upper extremity in the scapular plane. To determine whether these functional differences are also reflected in the molecular biochemistry of the supraspinatus muscles involved in these different locomotor modes, we used real-time polymerase chain reaction (RT-PCR) to analyze the expression of the myosin heavy chain (MHC) isoforms in supraspinatus muscles from modern humans and 12 species of pronograde and orthograde primates. The MHC expression pattern in the supraspinatus muscle of pronograde primates was consistent with its function as a tonic and postural muscle, whereas the MHC expression pattern observed in the supraspinatus muscle of nonhuman orthograde primates was that of a muscle that emphasizes speed, strength, and less resistance to fatigue. These findings are consistent with the role of the supraspinatus in the posture and locomotor modes of these groups of nonhuman primates. The humans included in the study had an expression pattern similar to that of the nonhuman orthograde primates. In conclusion, molecular analysis of skeletal muscles via RT-PCR can contribute to a better understanding of the morphological and functional characteristics of the primate musculoskeletal system.