http://www.molecular-cancer.com The latest research articles published by Molecular Cancer 2013-05-19T00:00:00Z MicroRNAs(miRNA) are noncoding RNAs of about 19--23 nucleotides that are crucial for many biological processes. Members of the microRNA-148/152(miR-148/152) family, which include microRNA-148a(miR-148a), microRNA-148b(miR-148b), and microRNA-152(miR-152), are expressed differently in tumor and nontumor tissues and are involved in the genesis and development of disease. Furthermore, members of the miR-148/152 family are important in the growth and development of normal tissues. Members of the miR-148/152 family regulate target genes and are regulated by methylation of CPG islands. In this review, we report recent studies on the expression of members of the miR-148/152 family, methylation of CPG islands, and their target genes in different diseases, as well as in normal tissues. http://www.molecular-cancer.com/content/12/1/43 Yue Chen Yong-Xi Song Zhen-Ning Wang Molecular Cancer 2013, null:43 2013-05-19T00:00:00Z doi:10.1186/1476-4598-12-43 /content/figures/1476-4598-12-43-toc.gif Molecular Cancer 1476-4598 ${item.volume} 43 2013-05-19T00:00:00Z PDF Background: It has been shown in many solid tumors that the overexpression of the pro-survival Bcl-2 family members Bcl-2/Bcl-xL and Mcl-1 confers resistance to a variety of chemotherapeutic agents. We designed the BH3 alpha-helix mimetic JY-1-106 to engage the hydrophobic BH3-binding grooves on the surfaces of both Bcl-xL and Mcl-1. Methods: JY-1-106--protein complexes were studied using molecular dynamics (MD) simulations and the SILCS methodology. We have evaluated the in vitro effects of JY-1-106 by using a fluorescence polarization (FP) assay, an XTT assay, apoptosis assays, and immunoprecipitation and western-blot assays. A preclinical human cancer xenograft model was used to test the efficacy of JY-1-106 in vivo. Results: MD and SILCS simulations of the JY-1-106--protein complexes indicated the importance of the aliphatic side chains of JY-1-106 to binding and successfully predicted the improved affinity of the ligand for Bcl-xL over Mcl-1. Ligand binding affinities were measured via an FP assay using a fluorescently labeled Bak-BH3 peptide in vitro. Apoptosis induction via JY-1-106 was evidenced by TUNEL assay and PARP cleavage as well as by Bax--Bax dimerization. Release of multi-domain Bak from its inhibitory binding to Bcl-2/Bcl-xL and Mcl-1 using JY-1-106 was detected via immunoprecipitation (IP) western blotting.At the cellular level, we compared the growth proliferation IC50s of JY-1-106 and ABT-737 in multiple cancer cell lines with various Bcl-xL and Mcl-1 expression levels. JY-1-106 effectively induced cell death regardless of the Mcl-1 expression level in ABT-737 resistant solid tumor cells, whilst toxicity toward normal human endothelial cells was limited. Furthermore, synergistic effects were observed in A549 cells using a combination of JY-1-106 and multiple chemotherapeutic agents. We also observed that JY-1-106 was a very effective agent in inducing apoptosis in metabolically stressed tumors. Finally, JY-1-106 was evaluated in a tumor-bearing nude mouse model, and was found to effectively repress tumor growth. Strong TUNEL signals in the tumor cells demonstrated the effectiveness of JY-1-106 in this animal model. No significant side effects were observed in mouse organs after multiple injections. Conclusions: Taken together, these observations demonstrate that JY-1-106 is an effective pan-Bcl-2 inhibitor with very promising clinical potential. http://www.molecular-cancer.com/content/12/1/42 Xiaobo Cao Jeremy Yap M Newell-Rogers Chander Peddaboina Weihua Jian Harry Papaconstantinou Dan Jupitor Arun Rai Kwan-Young Jung Richard Tubin Wenbo Yu Kenno Vanommeslaeghe Paul Wilder Alexander MacKerell Steven Fletcher Roy Smythe Molecular Cancer 2013, null:42 2013-05-16T00:00:00Z doi:10.1186/1476-4598-12-42 /content/figures/1476-4598-12-42-toc.gif Molecular Cancer 1476-4598 ${item.volume} 42 2013-05-16T00:00:00Z PDF Background: Patients with familial adenomatous polyposis (FAP) are at increased risk for the development of colorectal cancer. Surgery and chemoprevention are the most effective means to prevent cancer development. Thymoquinone (TQ) is considered the main compound of the volatile Nigella sativa seed oil and has been reported to possess anticarcinogenic properties. In this study we evaluated the chemopreventive properties of TQ in a mouse model of FAP. Methods: APCMin mice were fed with chow containing 37.5 mg/kg or 375 mg/kg TQ for 12 weeks. H&E stained intestine tissue sections were assessed for tumor number, localization, size, and grade. Immunohistochemistry for beta-catenin, c-myc, Ki-67 and TUNEL-staining was performed to investigate TQ's effect on major colorectal cancer pathways. TQ's impact on GSK-3beta and beta-catenin were studied in RKO cells. Results: 375 mg/kg but not 37.5 mg/kg TQ decreased the number of large polyps in the small intestine of APCMin mice. TQ induced apoptosis in the neoplastic tissue but not in the normal mucosa. Furthermore, upon TQ treatment, beta-catenin was retained at the membrane and c-myc decreased in the nucleus, which was associated with a reduced cell proliferation in the villi. In vitro, TQ activated GSK-3beta, which induced membranous localization of beta-catenin and reduced nuclear c-myc expression. Conclusions: In summary, TQ interferes with polyp progression in ApcMin mice through induction of tumor-cell specific apoptosis and by modulating Wnt signaling through activation of GSK-3beta. Nigella sativa oil (or TQ) might be useful as nutritional supplement to complement surgery and chemoprevention in FAP. http://www.molecular-cancer.com/content/12/1/41 Michaela Lang Melanie Borgmann Georg Oberhuber Rayko Evstatiev Kristine Jimenez Kyle Dammann Manuela Jambrich Vineeta Khare Christoph Campregher Robin Ristl Christoph Gasche Molecular Cancer 2013, null:41 2013-05-13T00:00:00Z doi:10.1186/1476-4598-12-41 /content/figures/1476-4598-12-41-toc.gif Molecular Cancer 1476-4598 ${item.volume} 41 2013-05-13T00:00:00Z PDF Background: Co-Activator Arginine Methyltransferase 1(CARM1) is an Estrogen Receptor (ER) cofactor that remodels chromatin for gene regulation via methylation of Histone3. We investigated CARM1 levels and localization across breast cancer tumors in a cohort of patients of either European or African ancestry. Methods: We analyzed CARM1 levels using tissue microarrays with over 800 histological samples from 549 female cancer patients from the US and Nigeria, Africa. We assessed associations between CARM1 expression localized to the nucleus and cytoplasm for 11 distinct variables, including; ER status, Progesterone Receptor status, molecular subtypes, ethnicity, HER2+ status, other clinical variables and survival. Results: We found that levels of cytoplasmic CARM1 are distinct among tumor sub-types and increased levels are associated with ER-negative (ER-) status. Higher nuclear CARM1 levels are associated with HER2 receptor status. EGFR expression also correlates with localization of CARM1 into the cytoplasm. This suggests there are distinct functions of CARM1 among molecular tumor types. Our data reveals a basal-like subtype association with CARM1, possibly due to expression of Epidermal Growth Factor Receptor (EGFR). Lastly, increased cytoplasmic CARM1, relative to nuclear levels, appear to be associated with self-identified African ethnicity and this result is being further investigated using quantified genetic ancestry measures. Conclusions: Although it is known to be an ER cofactor in breast cancer, CARM1 expression levels are independent of ER. CARM1 has distinct functions among molecular subtypes, as is indicative of its sub-cellular localization and it may function in subtype etiology. These sub-cellular localization patterns, indicate a novel role beyond its ER cofactor function in breast cancer. Differential localization among ethnic groups may be due to ancestry-specific polymorphisms which alter the gene product. http://www.molecular-cancer.com/content/12/1/40 Melissa Davis Xinyu Liu Shiyao Wang Jaxk Reeves Andrey Khramtsov Dezheng Huo Olufunmilayo Olopade Molecular Cancer 2013, null:40 2013-05-10T00:00:00Z doi:10.1186/1476-4598-12-40 /content/figures/1476-4598-12-40-toc.gif Molecular Cancer 1476-4598 ${item.volume} 40 2013-05-10T00:00:00Z PDF Background: The aryl hydrocarbon receptor (AhR) ligand 6-Formylindolo(3,2-b)carbazole (FICZ) has received increasing attention since its identification as an endogenous AhR ligand and a photoproduct of tryptophan. FICZ and its metabolites have been detected in human fluids. We recently reported that AhR promotes retinoic acid (RA)-induced granulocytic differentiation of HL-60 myeloblastic leukemia cells by restricting the nuclear abundance of the stem cell associated transcription factor Oct4. The standard clinical management of acute promyelocytic leukemia (APL) is differentiation induction therapy using RA. But RA is not effective for other myeloid leukemias, making the mechanism of RA-induced differentiation observed in a non-APL myeloid leukemia of interest. To our knowledge, this is the first study regarding the influence of FICZ on RA-induced differentiation in any type of leukemic blasts. Methods: Using flow cytometry and Western blotting assays, we determined the effects of FICZ on RA-induced differentiation of HL-60 human leukemia cells. All experiments were performed in triplicate. The groups RA and FICZ + RA were compared using the Paired-Samples T-Test. Western blot figures present the typical blots. Results: We demonstrate that FICZ enhances RA-induced differentiation, assessed by the expression of the membrane differentiation marker CD11b; cell cycle arrest; and the functional differentiation marker, inducible-oxidative metabolism. FICZ causes changes in signaling events that are known to drive differentiation, and notably augments the RA-induced sustained activation of the RAF/MEK/ERK axis of the mitogen-activated protein kinase (MAPK) cascade. FICZ also augments expression of the known MAPK signaling regulatory molecules c-Cbl, VAV1, pY458 p85 PI3K, Src-family kinases (SFKs), and IRF-1, a transcription factor associated with this putative signalsome that promotes RA-induced differentiation. Moreover, FICZ in combination with RA also increases expression of AhR and even more so of both Cyp1A2 and p47phox, which are known to be transcriptionally regulated by AhR. pY1021 PDGFRbeta, a marker associated with retinoic acid syndrome was also increased. Conclusions: Our data suggest that FICZ modulates intracellular signaling pathways and enhances RA-induced differentiation. http://www.molecular-cancer.com/content/12/1/39 Rodica Bunaciu Andrew Yen Molecular Cancer 2013, null:39 2013-05-09T00:00:00Z doi:10.1186/1476-4598-12-39 /content/figures/1476-4598-12-39-toc.gif Molecular Cancer 1476-4598 ${item.volume} 39 2013-05-09T00:00:00Z PDF Background: Infection with high-risk human papillomavirus (HR-HPV) genotypes, mainly HPV16 and HPV18, is a major risk factor for cervical cancer and responsible for its progression. While the transforming role of the HPV E6 and E7 proteins is more characterized, the molecular mechanisms of the oncogenic activity of the E5 product are still only partially understood, but appear to involve deregulation of growth factor receptor expression. Since the signaling of the transforming growth factor beta (TGFbeta) is known to play crucial roles in the epithelial carcinogenesis, aim of this study was to investigate if HPV16 E5 would modulate the TGF-BRII expression and TGFbeta/Smad signaling.FindingsThe HPV16 E5 mRNA expression pattern was variable in low-grade squamous intraepithelial lesions (LSIL), while homogeneously reduced in high-grade lesions (HSIL). Parallel analysis of TGFBRII mRNA showed that the receptor transcript levels were also variable in LSILs and inversely related to those of the viral protein. In vitro quantitation of the TGFBRII mRNA and protein in human keratinocytes expressing 16E5 in a dose-dependent and time-dependent manner showed a progressive down-modulation of the receptor. Phosphorylation of Smad2 and nuclear translocation of Smad4 were also decreased in E5-expressing cells stimulated with TGFbeta1. Conclusions: Taken together our results indicate that HPV16 E5 expression is able to attenuate the TGFbeta1/Smad signaling and propose that this loss of signal transduction, leading to destabilization of the epithelial homeostasis at very early stages of viral infection, may represent a crucial mechanism of promotion of the HPV-mediated cervical carcinogenesis. http://www.molecular-cancer.com/content/12/1/38 Deborah French Francesca Belleudi Maria Vittoria Mauro Francesca Mazzetta Salvatore Raffa Vincenza Fabiano Antonio Frega Maria Rosaria Torrisi Molecular Cancer 2013, null:38 2013-05-07T00:00:00Z doi:10.1186/1476-4598-12-38 /content/figures/1476-4598-12-38-toc.gif Molecular Cancer 1476-4598 ${item.volume} 38 2013-05-07T00:00:00Z PDF Background: In a previous report, we described the in vitro and in vivo antiproliferative and proapoptotic activity of a hydroxylated biphenyl (D6), a structural analogue of curcumin, on malignant melanoma and neuroblastoma tumours. In this paper, we investigated the molecular changes induced by such a compound, underlying cell growth arrest and apoptosis in melanoma cells. Results: To shed light on the mechanisms of action of D6, we firstly demonstrated its quick cellular uptake and subsequent block of cell cycle in G2/M phase transition. A gene expression profile analysis of D6-treated melanoma cells and fibroblasts was then carried out on high density microarrays, to assess gene expression changes induced by this compound. The expression profile study evidenced both an induction of stress response pathways and a modulation of cell growth regulation mechanisms. In particular, our data suggest that the antiproliferative and proapoptotic activities of D6 in melanoma could be partially driven by up-regulation of the p53 signalling pathways as well as by down-regulation of the PI3K/Akt and NF-kB pathways. Modulation of gene expression due to D6 treatment was verified by western blot analysis for single proteins of interest, confirming the results from the gene expression profile analysis. Conclusions: Our findings contribute to the understanding of the mechanisms of action of D6, through a comprehensive description of the molecular changes induced by this compound at the gene expression level, in agreement with the previously reported anti-tumour effects on melanoma cells. http://www.molecular-cancer.com/content/12/1/37 Carla Rozzo Manuela Fanciulli Cristina Fraumene Antonio Corrias Tiziana Cubeddu Ilaria Sassu Sara Cossu Valentina Nieddu Grazia Galleri Emanuela Azara Maria Antonietta Dettori Davide Fabbri Giuseppe Palmieri Marina Pisano Molecular Cancer 2013, null:37 2013-05-04T00:00:00Z doi:10.1186/1476-4598-12-37 /content/figures/1476-4598-12-37-toc.gif Molecular Cancer 1476-4598 ${item.volume} 37 2013-05-04T00:00:00Z XML Background: The t(9;22)(q34;q11) generating the BCR/ABL1 fusion gene represents the cytogenetic hallmark of chronic myeloid leukemia (CML). About 5–10% of CML cases show variant translocations with the involvement of other chromosomes in addition to chromosomes 9 and 22. The molecular bases of biological differences between CML patients with classic and variant t(9;22) have never been clarified.FindingsIn this study, we performed gene expression microarray analysis to compare CML patients bearing variant rearrangements and those with classic t(9;22)(q34;q11). We identified 59 differentially expressed genes significantly associated with the two analyzed groups. The role of specific candidate genes such as TRIB1 (tribbles homolog 1), PTK2B (protein tyrosine kinase 2 beta), and C5AR1 (complement component 5a receptor 1) is discussed. Conclusions: Our results reveal that in CML cases with variant t(9;22) there is an enhancement of the MAPK pathway deregulation and show that kinases are a common target of molecular alterations in hematological disorders. http://www.molecular-cancer.com/content/12/1/36 Francesco Albano Antonella Zagaria Luisa Anelli Nicoletta Coccaro Luciana Impera Crescenzio Minervini Angela Minervini Antonella Rossi Giuseppina Tota Paola Casieri Giorgina Specchia Molecular Cancer 2013, null:36 2013-05-04T00:00:00Z doi:10.1186/1476-4598-12-36 /content/figures/1476-4598-12-36-toc.gif Molecular Cancer 1476-4598 ${item.volume} 36 2013-05-04T00:00:00Z XML Background: The eukaryotic translation initiation factor 5A1 (eIF5A1) is a highly conserved protein involved in many cellular processes including cell division, translation, apoptosis, and inflammation. Induction of apoptosis is the only function of eIF5A1 that is known to be independent of post-translational hypusine modification. In the present study, we investigated the involvement of mitogen- and stress-activated protein kinases during apoptosis of A549 lung cancer cells infected with adenovirus expressing eIF5A1 or a mutant of eIF5A1 that cannot be hypusinated (eIF5A1K50A). Methods: Using adenoviral-mediated transfection of human A549 lung cancer cells to over-express eIF5A1 and eIF5A1K50A, the mechanism by which unhypusinated eIF5A1 induces apoptosis was investigated by Western blotting, flow cytometry, and use of MAPK and p53 inhibitors. Results: Phosphorylation of ERK, p38 MAPK, and JNK was observed in response to adenovirus-mediated over-expression of eIF5A1 or eIF5A1K50A, along with phosphorylation and stabilization of the p53 tumor suppressor protein. Synthetic inhibitors of p38 and JNK kinase activity, but not inhibitors of ERK1/2 or p53 activity, significantly inhibited apoptosis induced by Ad-eIF5A1. Importantly, normal lung cells were more resistant to apoptosis induced by eIF5A1 and eIF5A1K50A than A549 lung cancer cells. Conclusions: Collectively these data indicate that p38 and JNK MAP kinase signaling are important for eIF5A1-induced cell death and that induction of apoptosis was not dependent on p53 activity. http://www.molecular-cancer.com/content/12/1/35 Catherine Taylor Qifa Zheng Zhongda Liu John Thompson Molecular Cancer 2013, null:35 2013-05-02T00:00:00Z doi:10.1186/1476-4598-12-35 /content/figures/1476-4598-12-35-toc.gif Molecular Cancer 1476-4598 ${item.volume} 35 2013-05-02T00:00:00Z PDF Background: Prior to the introduction of tamoxifen, high dose estradiol was used to treat breast cancer patients with similar efficacy as tamoxifen, albeit with some undesirable side effects. There is renewed interest to utilize estradiol to treat endocrine resistant breast cancers, especially since findings from several preclinical models and clinical trials indicate that estradiol may be a rational second-line therapy in patients exhibiting resistance to tamoxifen and/or aromatase inhibitors. We and others reported that breast cancer patients bearing protein kinase C alpha (PKCalpha)- expressing tumors exhibit endocrine resistance and tumor aggressiveness. Our T47D:A18/PKCalpha preclinical model is tamoxifen resistant, hormone independent, yet is inhibited by 17beta-estradiol (E2) in vivo. We previously reported that E2-induced T47D:A18/PKCalpha tumor regression requires extranuclear ERalpha and interaction with the extracellular matrix. Methods: T47D:A18/PKCalpha cells were grown in vitro using two-dimensional (2D) cell culture, three dimensional (3D) Matrigel and in vivo by establishing xenografts in athymic mice. Immunofluoresence confocal microscopy and co-localization were applied to determine estrogen receptor alpha (ERalpha) subcellular localization. Co-immunoprecipitation and western blot were used to examine interaction of ERalpha with caveolin-1. Results: We report that although T47D:A18/PKCalpha cells are cross-resistant to raloxifene in cell culture and in Matrigel, raloxifene induces regression of tamoxifen-resistant tumors. ERalpha rapidly translocates to extranuclear sites during T47D:A18/PKCalpha tumor regression in response to both raloxifene and E2, whereas ERalpha is primarily localized in the nucleus in proliferating tumors. E2 treatment induced complete tumor regression whereas cessation of raloxifene treatment resulted in tumor regrowth accompanied by re-localization of ERalpha to the nucleus. T47D:A18/neo tumors that do not overexpress PKCalpha maintain ERalpha in the nucleus during tamoxifen-mediated regression. An association between ERalpha and caveolin-1 increases in tumors regressing in response to E2. Conclusions: Extranuclear ERalpha plays a role in the regression of PKCalpha overexpressing tamoxifen-resistant tumors. These studies underline the unique role of extranuclear ERalpha in E2- and raloxifene-induced tumor regression that may have implications for treatment of endocrine-resistant PKCalpha expressing tumors encountered in the clinic. http://www.molecular-cancer.com/content/12/1/34 Bethany Perez White Mary Molloy Huiping Zhao Yiyun Zhang Debra Tonetti Molecular Cancer 2013, null:34 2013-05-01T00:00:00Z doi:10.1186/1476-4598-12-34 /content/figures/1476-4598-12-34-toc.gif Molecular Cancer 1476-4598 ${item.volume} 34 2013-05-01T00:00:00Z PDF