http://www.molecular-cancer.com The latest research articles published by Molecular Cancer 2013-05-25T00:00:00Z Background: Deficiency in tuberin results in activation the mTOR pathway and leads to accumulation of cell matrix proteins. The mechanisms by which tuberin regulates fibrosis in kidney angiomyolipomas (AMLs) of tuberous sclerosis patients are not fully known.MethodIn the present study, we investigated the potential role of tuberin/mTOR pathway in the regulation of cell fibrosis in AML cells and kidney tumor tissue from tuberous sclerosis complex (TSC) patients. Results: AML cells treated with rapamycin shows a significant decrease in mRNA and protein expression as well as in promoter transcriptional activity of alpha-smooth muscle actin (alpha-SMA) compared to untreated cells. In addition, cells treated with rapamycin significantly decreased the protein expression of the transcription factor YY1. Rapamycin treatment also results in the redistribution of YY1 from the nucleus to cytoplasm in AML cells. Moreover, cells treated with rapamycin resulted in a significant reduce of binding of YY1 to the alphaSMA promoter element in nuclear extracts of AML cells. Kidney angiomyolipoma tissues from TSC patients showed lower levels of tuberin and higher levels of phospho-p70S6K that resulted in higher levels of mRNA and protein of alphaSMA expression compared to control kidney tissues. In addition, most of the alpha-SMA staining was identified in the smooth muscle cells of AML tissues. YY1 was also significantly increased in tumor tissue of AMLs compared to control kidney tissue suggesting that YY1 plays a major role in the regulation of alphaSMA. Conclusions: These data comprise the first report to provide one mechanism whereby rapamycin might inhibit the cell fibrosis in kidney tumor of TSC patients. http://www.molecular-cancer.com/content/12/1/49 Sitai Liang Gabriela Cuevas Shaza Tizani Tiffanie Salas Huijuan Liu Baojie Li Samy Habib Molecular Cancer 2013, null:49 2013-05-25T00:00:00Z doi:10.1186/1476-4598-12-49 /content/figures/1476-4598-12-49-toc.gif Molecular Cancer 1476-4598 ${item.volume} 49 2013-05-25T00:00:00Z PDF Background: One of the most important areas of Raman medical diagnostics is identification and characterization of cancerous and noncancerous tissues. The methods based on Raman scattering has shown significant potential for probing human breast tissue to provide valuable information for early diagnosis of breast cancer. A vibrational fingerprint from the biological tissue provides information which can be used to identify, characterize and discriminate structures in breast tissue, both in the normal and cancerous environment. Results: The paper reviews recent progress in understanding structure and interactions at biological interfaces of the human tissue by using confocal Raman imaging and IR spectroscopy. The important differences between the noncancerous and cancerous human breast tissues were found in regions characteristic for vibrations of carotenoids, fatty acids, proteins, and interfacial water. Particular attention was paid to the role played by unsaturated fatty acids and their derivatives as well as carotenoids and interfacial water. Conclusions: We demonstrate that Raman imaging has reached a clinically relevant level in regard to breast cancer diagnosis applications. The results presented in the paper may have serious implications on understanding mechanisms of interactions in living cells under realistically crowded conditions of biological tissue. http://www.molecular-cancer.com/content/12/1/48 Jakub Surmacki Jacek Musial Radzislaw Kordek Halina Abramczyk Molecular Cancer 2013, null:48 2013-05-24T00:00:00Z doi:10.1186/1476-4598-12-48 /content/figures/1476-4598-12-48-toc.gif Molecular Cancer 1476-4598 ${item.volume} 48 2013-05-24T00:00:00Z PDF Background: An in vitro model was developed to understand if celecoxib could synergize with Mitomycin C (MMC), commonly used for the prevention of non-muscle invasive bladder cancer recurrence, and eventually elucidate if the mechanism of interaction involves multi drug resistance (MDR) transporters. Methods: UMUC-3, a non COX-2 expressing bladder cancer cell line, and UMUC-3-CX, a COX-2 overexpressing transfectant, as well as 5637, a COX-2 overexpressing cell line, and 5637si-CX, a non COX-2 expressing silenced 5637 cell line, were used in the present study. The expression of COX-2 and MDR pumps (P-gp, MDR-1 and BCRP) was explored through western blot. The anti-proliferative effect of celecoxib and MMC was studied with MTT test. Three biological permeability assays (Drug Transport Experiment, Substrate Transporter Inhibition, and ATP cell depletion) were combined to study the interaction between MDR transporters and celecoxib. Finally, the ability of celecoxib to restore MMC cell accumulation was investigated. Results: The anti-proliferative effect of celecoxib and MMC were investigated alone and in co-administration, in UMUC-3, UMUC-3-CX, 5637 and 5637si-CX cells. When administered alone, the effect of MMC was 8-fold greater in UMUC-3. However, co-administration of 1 muM, 5 muM, and 10 muM celecoxib and MMC caused a 2,3-fold cytotoxicity increase in UMUC-3-CX cell only. MMC cytotoxicity was not affected by celecoxib co-administration either in 5637, or in 5637si-CX cells. As a result of all finding from the permeability experiments, celecoxib was classified as P-gp unambiguous substrate: celecoxib is transported by MDR pumps and interferes with the efflux of MMC. Importantly, among all transporters, BCRP was only overexpressed in UMUC-3-CX cells, but not in 5637 and 5637si-CX. Conclusions: The UMUC-3-CX cell line resembles a more aggressive phenotype with a lower response to MMC compared to the wt counterpart. However, the administration of celecoxib in combination to MMC causes a significant and dose dependent gain of the anti-proliferative activity. This finding may be the result of a direct interaction between celecoxib and MDR transporters. Indeed, BCRP is overexpressed in UMUC-3-CX, but not in UMUC-3, 5637, and 5637si-CX, in which celecoxib is ineffective. http://www.molecular-cancer.com/content/12/1/47 Vincenzo Pagliarulo Patrizia Ancona Mauro Niso Nicola Colabufo Marialessandra Contino Luigi Cormio Amalia Azzariti Arcangelo Pagliarulo Molecular Cancer 2013, null:47 2013-05-24T00:00:00Z doi:10.1186/1476-4598-12-47 /content/figures/1476-4598-12-47-toc.gif Molecular Cancer 1476-4598 ${item.volume} 47 2013-05-24T00:00:00Z PDF Background: Dysregulation of the PI3Kinase/AKT pathway is involved in the pathogenesis of many human malignancies. In acute leukemia, the AKT pathway is frequently activated, however mutations in the PI3K/AKT pathway are uncommon. In some cases, constitutive AKT activation can be linked to gain-of-function tyrosine kinase (TK) mutations upstream of the PI3K/AKT pathway. Inhibitors of the PI3K/AKT pathway are attractive candidates for cancer drug development, but so far clinical efficacy of PI3K inhibitors against various neoplasms has been moderate. Furthermore, specific MTORC1 inhibitors, acting downstream of AKT, have the disadvantage of activating AKT via feed-back mechanisms. We now evaluated the antitumor efficacy of NVP-BGT226, a novel dual pan-PI3K and MTORC1/2 inhibitor, in acute leukemia. Methods: Native leukemia blasts were stained to analyze for AKT phosphorylation levels on a flow cytometer. Efficacy of NVP-BGT226 in comparison to a second dual inhibitor, NVP-BEZ235, was determined with regard to cellular proliferation, autophagy, cell cycle regulation and induction of apoptosis in in vitro and ex vivo cellular assays as well as on the protein level. An isogenic AKT-autoactivated Ba/F3 model, different human leukemia cell lines as well as native leukemia patient blasts were studied. Isobologram analyses were set up to calculate for (super) additive or antagonistic effects of two agents. Results: We show, that phosphorylation of AKT is frequently augmented in acute leukemia. NVP-BGT226 as well as NVP-BEZ235 profoundly and globally suppress AKT signaling pathways, which translates into potent antiproliferative effects. Furthermore, NVP-BGT226 has potent proapoptotic effects in vitro as well as in ex vivo native blasts. Surprisingly and in contrast, NVP-BEZ235 leads to a profound G1/G0 arrest preventing significant induction of apoptosis. Combination with TK inhibitors, which are currently been tested in the treatment of acute leukemia subtypes, overcomes cell cycle arrest and results in (super)additive proapoptotic effects for NVP-BGT226 -- but also for NVP-BEZ235. Importantly, mononuclear donor cells show lower phospho-AKT expression levels and consequently, relative insensitivity towards dual PI3K-MTORC1/2 inhibition. Conclusions: Our data suggest a favorable antileukemic profile for NVP-BGT226 compared to NVP-BEZ235 -- which provides a strong rationale for clinical evaluation of the dual PI3K-MTORC1/2 inhibitor NVP-BGT226 in acute leukemia. http://www.molecular-cancer.com/content/12/1/46 Kerstin Kampa-Schittenhelm Michael Heinrich Figen Akmut Katharina Rasp Barbara Illing Hartmut Döhner Konstanze Döhner Marcus Schittenhelm Molecular Cancer 2013, null:46 2013-05-24T00:00:00Z doi:10.1186/1476-4598-12-46 /content/figures/1476-4598-12-46-toc.gif Molecular Cancer 1476-4598 ${item.volume} 46 2013-05-24T00:00:00Z PDF Background: Although mammary cancer (MC) is the most common malignant neoplasia in women, the mortality for this cancer has decreased principally because of early detection and the use of neoadjuvant chemotherapy. Of several preparations that cause MC regression, doxorubicin (DOX) is the most active, first-line monotherapeutic. Nevertheless, its use is limited due to the rapid development of chemoresistance and to the cardiotoxicity caused by free radicals. In previous studies we have shown that supplementation with molecular iodine (I2) has a powerful antineoplastic effect in methylnitrosourea (MNU)-induced experimental models of MC. These studies also showed a consistent antioxidant effect of I2 in normal and tumoral tissues. Methods: Here, we analyzed the effect of I2 in combination with DOX treatment in female Sprague Dawley rats with MNU-induced MC. In the first experiment (short) animals were treated with the therapeutic DOX dose (16 mg/kg) or with lower doses (8 and 4 mg/Kg), in each case with and without 0.05% I2 in drinking water. Iodine treatment began on day 0, a single dose of DOX was injected (ip) on day 2, and the analysis was carried out on day 7. In the second experiment (long) animals with and without iodine supplement were treated with one or two injections of 4 mg/kg DOX (on days 0 and 14) and were analyzed on day 56. Results: At all DOX doses, the short I2 treatment induced adjuvant antineoplastic effects (decreased tumor size and proliferating cell nuclear antigen level) with significant protection against body weight loss and cardiotoxicity (creatine kinase MB, cardiac lipoperoxidation, and heart damage). With long-term I2, mammary tumor tissue became more sensitive to DOX, since a single injection of the lowest dose of DOX (4 mg/Kg) was enough to stop tumor progression and a second DOX4 injection on day 14 caused a significant and rapid decrease in tumor size, decreased the expression of chemoresistance markers (Bcl2 and survivin), and increased the expression of the apoptotic protein Bax and peroxisome proliferator-activated receptor type gamma. Conclusions: The DOX-I2 combination exerts antineoplastic, chemosensitivity, and cardioprotective effects and could be a promising strategy against breast cancer progression. http://www.molecular-cancer.com/content/12/1/45 Yunuen Alfaro Guadalupe Delgado Alfonso Cárabez Brenda Anguiano Carmen Aceves Molecular Cancer 2013, null:45 2013-05-24T00:00:00Z doi:10.1186/1476-4598-12-45 /content/figures/1476-4598-12-45-toc.gif Molecular Cancer 1476-4598 ${item.volume} 45 2013-05-24T00:00:00Z PDF Background: All-trans retinoic acid (ATRA) is currently being used in clinical trials for cancer treatment. The use of ATRA is limited because some cancers, such as lung cancer, show resistance to treatment. However, little is known about the molecular mechanisms that regulate resistance to ATRA treatment. Akt is a kinase that plays a key role in cell survival and cell invasion. Akt is often activated in lung cancer, suggesting its participation in resistance to chemotherapy. In this study, we explored the hypothesis that activation of the Akt pathway promotes resistance to ATRA treatment at the inhibition of cell survival and invasion in lung cancer. We aimed to provide guidelines for the proper use of ATRA in clinical trials and to elucidate basic biological mechanisms of resistance. Results: We performed experiments using the A549 human lung adenocarcinoma cell line. We found that ATRA treatment promotes PI3k-Akt pathway activation through transcription-independent mechanisms. Interestingly, ATRA treatment induces the translocation of RARalpha to the plasma membrane, where it colocalizes with Akt. Immunoprecipitation assays showed that ATRA promotes Akt activation mediated by RARalpha-Akt interaction. Activation of the PI3k-Akt pathway by ATRA promotes invasion through Rac-GTPase, whereas pretreatment with 15e (PI3k inhibitor) or over-expression of the inactive form of Akt blocks ATRA-induced invasion. We also found that treatment with ATRA induces cell survival, which is inhibited by 15e or over-expression of an inactive form of Akt, through a subsequent increase in the levels of the active form of caspase-3. Finally, we showed that over-expression of the active form of Akt significantly decreases expression levels of the tumor suppressors RARbeta2 and p53. In contrast, over-expression of the inactive form of Akt restores RARbeta2 expression in cells treated with ATRA, indicating that activation of the PI3k-Akt pathway inhibits the expression of ATRA target genes. Conclusion: Our results demonstrate that rapid activation of Akt blocks transcription-dependent mechanism of ATRA, promotes invasion and cell survival and confers resistance to retinoic acid treatment in lung cancer cells. These findings provide an incentive for the design and clinical testing of treatment regimens that combine ATRA and PI3k inhibitors for lung cancer treatment. http://www.molecular-cancer.com/content/12/1/44 Alejandro García-Regalado Miguel Vargas Alejandro García-Carrancá Elena Aréchaga-Ocampo Claudia González-De la Rosa Molecular Cancer 2013, null:44 2013-05-21T00:00:00Z doi:10.1186/1476-4598-12-44 /content/figures/1476-4598-12-44-toc.gif Molecular Cancer 1476-4598 ${item.volume} 44 2013-05-21T00:00:00Z PDF 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 α-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 Jiang 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 XML 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 β-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-3β and β-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, β-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-3β, which induced membranous localization of β-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-3β. 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 XML 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 XML