Showing papers in "Cellular Oncology in 2015"
TL;DR: This concise review of three classes of long non-coding RNAs describes their appeal as targets and as drugs, while pointing out the limitations that still lie ahead of their definitive entry into clinical practice.
Abstract: Long non-coding RNAs (lncRNAs, pseudogenes and circRNAs) have recently come into light as powerful players in cancer pathogenesis and it is becoming increasingly clear that they have the potential of greatly contributing to the spread and success of personalized cancer medicine. In this concise review, we briefly introduce these three classes of long non-coding RNAs. We then discuss their applications as diagnostic and prognostic biomarkers. Finally, we describe their appeal as targets and as drugs, while pointing out the limitations that still lie ahead of their definitive entry into clinical practice.
88 citations
TL;DR: It is found that over-expression of miR-138-5p may serve as a novel approach for the treatment of patients with pancreatic cancer and that silencing of FOXC1 by siRNA had an inhibitory effect on pancreaticcancer cell growth.
Abstract: Purpose
The prognosis of pancreatic cancer ranks among the worst of all cancer types, which is primarily due to the fact that during the past decades little progress has been made in its diagnosis and treatment. Here, we set out to investigate the role of microRNA 138 (miR-138-5p) in the regulation of pancreatic cancer cell growth and to assess its role as putative therapeutic target.
76 citations
TL;DR: Targeted disruption of the NF-κB signaling pathway may profoundly impair the adverse phenotype of CSCs and may provide a therapeutic opportunity to remove the CSC fraction, and recent evidence shows that such targeted strategies may be useful in adjuvant chemo-preventive settings.
Abstract: Cancer stem cells (CSCs) are regulated by several signaling pathways that ultimately control their maintenance and expansion. NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) forms a protein complex that controls DNA transcription and, as such, plays an important role in proliferation, inflammation, angiogenesis, invasion and metastasis. The NF-κB signaling pathway, which has been found to be constitutively activated in CSCs from a variety of cancers, participates in the maintenance, expansion, proliferation and survival of CSCs. Targeted disruption of this pathway may profoundly impair the adverse phenotype of CSCs and may provide a therapeutic opportunity to remove the CSC fraction. In particular, it may be attractive to use specific NF-κB inhibitors in chronic therapeutic schemes to reduce disease progression. Exceptional low toxicity profiles of these inhibitors are a prerequisite for use in combined treatment regimens and to avoid resistance. Although still preliminary, recent evidence shows that such targeted strategies may be useful in adjuvant chemo-preventive settings.
70 citations
TL;DR: The data indicate that CGA plays a role in the suppression of angiogenesis via inhibition of the HIF-1α/AKT pathway, and may represent a novel therapeutic option for the treatment of (lung) cancer.
Abstract: The hypoxia-inducible factor-1 (HIF-1) is known to play an important role in cellular responses to hypoxia, including the transcriptional activation of a number of genes involved in tumor angiogenesis. Chlorogenic acid (CGA), one of the most abundant polyphenols in the human diet, has been reported to inhibit cancer cell growth. The effect of CGA on tumor angiogenesis and its underlying mechanisms are, as yet, unknown. The effect of CGA on HIF-1α expression was assessed by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) assays in A549 lung cancer cells. The transcriptional activity of the HIF-1 complex was confirmed using a luciferase assay. To assess whether angiogenic factors are increased under hypoxic conditions in these cells, vascular endothelial growth factor (VEGF) expression levels were measured by RT-PCR and Western blotting. The direct effect of CGA on human vascular endothelial cells (HUVEC) under hypoxic conditions was analyzed using in vitro assays, including tube-formation, wound healing and Transwell invasion assays. To investigate the effect of CGA on angiogenesis in vivo, we performed a Matrigel plug assay in a mouse model. Finally, the effect of CGA on AKT and ERK activation (phosphorylation) as a putative mechanism underlying the effect of CGA on VEGF-mediated angiogenesis inhibition was assessed using Western blotting. We found that CGA significantly decreases the hypoxia-induced HIF-1α protein level in A549 cells, without changing its mRNA level. CGA was, however, found to suppress the transcriptional activity of HIF-1α under hypoxic conditions, leading to a decrease in the expression of its downstream target VEGF. We also found that CGA can block hypoxia-stimulated angiogenesis in vitro and VEGF-stimulated angiogenesis in vivo using HUVEC cells. In addition, we found that CGA can inhibit the HIF-1α/AKT signaling pathway, which plays an important role in VEGF activation and angiogenesis. Our data indicate that CGA plays a role in the suppression of angiogenesis via inhibition of the HIF-1α/AKT pathway. CGA may represent a novel therapeutic option for the treatment of (lung) cancer.
69 citations
TL;DR: This work provides evidence for the involvement of specific miRNAs in triple-negative breast cancer development through regulating BRCA1 expression.
Abstract: Background
Familial triple-negative breast cancers are often linked to mutations in the BRCA1 tumor suppressor gene. In sporadic triple-negative breast cancers BRCA1 is frequently inactivated at the transcriptional level, and it has been reported that this inactivation may be brought about by promoter methylation. More recently, it was found that BRCA1 may also be regulated at the post-transcriptional level by miRNAs. Here, we explored the expression of putative BRCA1-regulating miRNAs in sporadic human triple-negative breast cancer cells.
63 citations
TL;DR: The data suggest that p27Kip1 down-regulation in cervical cancer cells is primarily regulated through PI3K/AKT-mediated proteasomal degradation and may form a basis for the design of novel cervical cancer therapies.
Abstract: The cyclin-dependent kinase inhibitor p27Kip1 is known to act as a putative tumor suppressor in several human cancers, including cervical cancer. Down-regulation of p27Kip1 may occur either through transcription inhibition or through phosphorylation-dependent proteolytic degradation. As yet, the mechanism underlying p27Kip1 down-regulation and its putative downstream effects on cervical cancer development are poorly understood. Here we assessed the expression and sub-cellular localization of p27Kip1 and its effects on proliferation, cell cycle progression and (inhibition of) apoptosis in cervical cancer cells. Primary cervical cancer samples (n = 70), normal cervical tissue samples (n = 30) and cervical cancer-derived cell lines (n = 8) were used to assess the expression of p27Kip1 and AKT1 by RT-PCR, Western blotting and immunohistochemistry, respectively. The effects of the PI3K inhibitor LY294004 and the proteasome inhibitor MG132 on cervical cancer cell proliferation were investigated using a MTT assay. Apoptosis and cell cycle analyses were carried out using flow cytometry, and sub-cellular p27Kip1 localization analyses were carried out using immunofluorescence assays. We observed p27Kip1 down-regulation (p = 0.045) and AKT1 up-regulation (p = 0.046) in both the primary cervical cancer samples and the cervical cancer-derived cell lines, compared to the normal cervical tissue samples tested. Treatment of cervical cancer-derived cell lines with the PI3K inhibitor LY294002 resulted in a reduced AKT1 activity. We also observed a dose-dependent inhibition of cell viability after treatment of these cell lines with the proteasome inhibitor MG132. Treatment of the cells with LY294002 resulted in a G1 cell cycle arrest, a nuclear expression of p27Kip1, and a cytoplasmic p27Kip1 accumulation after subsequent treatment with MG132. Additionally, we found that the synergistic effect of MG132 and LY294002 resulted in a sub-G1 cell cycle arrest and apoptosis induction through poly (ADP-ribose) polymerase (PARP) cleavage. Our data suggest that p27Kip1 down-regulation in cervical cancer cells is primarily regulated through PI3K/AKT-mediated proteasomal degradation. The observed synergistic effect of the MG132 and LY294002 inhibitors may form a basis for the design of novel cervical cancer therapies.
60 citations
TL;DR: Hesperidin elicits an in vitro growth inhibitory effect on NSCLC cells by modulating immune response-related pathways that affect apoptosis, and may serve as a novel anti-proliferative agent for non-small cell lung cancer.
Abstract: Purpose
Hesperidin, a glycoside flavonoid, is thought to act as an anti-cancer agent, since it has been found to exhibit both pro-apoptotic and anti-proliferative effects in several cancer cell types The mechanisms underlying hesperidin-induced growth arrest and apoptosis are, however, not well understood Here, we aimed to investigate the anti-proliferative and apoptotic effects of hesperidin on non-small cell lung cancer (NSCLC) cells and to investigate the mechanisms involved
59 citations
TL;DR: The data indicate that tumor cells can develop (cross-) resistance to TKIs, and that such resistance includes increased intracellular drug accumulation accompanied by increased lysosomal storage.
Abstract: Purpose
When during cancer treatment resistance to a tyrosine kinase inhibitor (TKI) occurs, switching to another TKI is often considered as a reasonable option. Previously, we reported that resistance to sunitinib may be caused by increased lysosomal sequestration, leading to increased intracellular lysosomal storage and, thereby, inactivity. Here, we studied the effect of several other TKIs on the development of (cross-) resistance.
52 citations
TL;DR: It is suggested that methylation-mediated suppression of the ECRG4 gene occurs frequently in NPC and that restoration of its expression may have therapeutic benefits.
Abstract: Background
Human nasopharyngeal carcinoma (NPC) is a malignant type of cancer with an increasing incidence. As yet, however, molecular biomarkers with a strong diagnostic impact and a major therapeutic promise have remained elusive. Here, we identified the esophageal carcinoma related gene 4 (ECRG4) as a novel candidate tumor suppressor gene and a promising therapeutic target for NPC.
42 citations
TL;DR: Nuclear KLF15 expression suppresses breast cancer cell proliferation at least partially through p21 up-regulation and subsequent cell cycle arrest, and is a pivotal suppressor of the G1 to S phase transition of the cell cycle.
Abstract: Purpose
Kruppel-like factor 15 (KLF15) is a transcription factor that is involved in various biological processes, including cellular proliferation, differentiation and death. In addition, KLF15 has recently been implicated in the development of several human malignancies, including breast cancer. In vitro breast cancer studies have pointed at a putative role in the regulation of cell proliferation. As yet, however, KLF15 expression analyses in primary human breast cancers have not been reported. Here, we set out to investigate the clinical and biological significance of KLF15 expression in human breast cancers.
41 citations
TL;DR: Specific chromosomal abnormalities and gene mutations may serve as diagnostic and prognostic indicators for disease progression and survival and the efficacy of novel therapeutics should be tested according to the presence of these molecular lesions in CLL patients.
Abstract: Backgrounds
Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults and is characterized by a clonal accumulation of mature apoptosis-resistant neoplastic cells. It is also a heterogeneous disease with a variable clinical outcome. Here, we present a review of currently known (epi)genetic alterations that are related to the etiology, progression and chemo-refractoriness of CLL. Relevant literature was identified through a PubMed search (1994–2014) of English-language papers using the terms CLL, signaling pathway, cytogenetic abnormality, somatic mutation, epigenetic alteration and micro-RNA.
TL;DR: In vivo xenograft models may be more appropriate than in vitro clonogenic assays to assess the anti-tumor activity of TGF-β inhibitors such as galunisertib, and results suggest that, next to intrinsic, also extrinsic or microenvironmental factors can affect galun isertib response.
Abstract: Purpose
The transforming growth factor-beta (TGF-β) signaling pathway is known to play a critical role in promoting tumor growth. Consequently, blocking this pathway has been found to inhibit tumor growth. In order to achieve an optimal anti-tumor effect, however, it remains to be established whether blocking the TGF-β signaling pathway alone is sufficient, or whether the tumor microenvironment plays an additional, possibly synergistic, role.
TL;DR: The results suggest that emodin exhibits an anti-tumor effect on gynecological cancer-derived cells, possibly through multiple mechanisms including the induction of apoptosis and autophagy, the arrest of the cell cycle, and the inhibition of angiogenesis.
Abstract: Although an anti-tumor effect of emodin has been reported before, its effect on human gynecological cancer cells has so far not been studied. Here, we assessed the effect of emodin on cervical cancer-derived (Hela), choriocarcinoma-derived (JAR) and ovarian cancer-derived (HO-8910) cells, and investigated the possible underlying molecular and cellular mechanisms. The respective cells were treated with 0, 5, 10 or 15 μM emodin for 72 h. Subsequently, MTT and Transwell in vitro migration assays revealed that emodin significantly decreased the viability and invasive capacity of the gynecological cancer-derived cells tested. We found that emodin induced apoptosis and significantly decreased mitochondrial membrane potential and ATP release in these cells. We also found that emodin may exert its apoptotic effects via regulating the activity of caspase-9 and the expression of cleaved-caspase-3. Moreover, we found that emodin induced a cell cycle arrest at the G0/G1 phase, possibly through down-regulating the key cell cycle regulators Cyclin D and Cyclin E. Interestingly, emodin also led to autophagic cell death, as revealed by increased MAP LC3 expression, a marker of the autophagosome, and decreased expression of the autophagy regulators Beclin-1 and Atg12-Atg5. Finally, we found that the protein levels of both VEGF and VEGFR-2 were significantly decreased in emodin-treated cells, suggesting an anti-angiogenic effect of emodin on gynecological cancer-derived cells. Our results suggest that emodin exhibits an anti-tumor effect on gynecological cancer-derived cells, possibly through multiple mechanisms including the induction of apoptosis and autophagy, the arrest of the cell cycle, and the inhibition of angiogenesis. Our findings may provide a basis for the design of potential emodin-based strategies for the treatment of gynecological tumors.
TL;DR: This work screened the literature for gene expression studies published since the turn of the century on thirteen of the most prevalent human cancers worldwide and recommended that a combination of PPIA and either GAPDH, ACTB, HPRT and TBP, or appropriate combinations of two or three of these genes, should be employed in future studies, to ensure that results from different studies on different human cancers can be harmonized.
Abstract: Gene expression studies are increasingly used to provide valuable information on the diagnosis and prognosis of human cancers. Also, for in vitro and in vivo experimental cancer models gene expression studies are widely used. The complex algorithms of differential gene expression analyses require normalization of data against a reference or normalizer gene, or a set of such genes. For this purpose, mostly invariant housekeeping genes are used. Unfortunately, however, there are no consensus (housekeeping) genes that serve as reference or normalizer for different human cancers. In fact, scientists have employed a wide range of reference genes across different types of cancer for normalization of gene expression data. As a consequence, comparisons of these data and/or data harmonizations are difficult to perform and challenging. In addition, an inadequate choice for a reference gene may obscure genuine changes and/or result in erroneous gene expression data comparisons. In our effort to highlight the importance of selecting the most appropriate reference gene(s), we have screened the literature for gene expression studies published since the turn of the century on thirteen of the most prevalent human cancers worldwide. Based on the analysis of the data at hand, we firstly recommend that in each study the suitability of candidate reference gene(s) should carefully be evaluated in order to yield reliable differential gene expression data. Secondly, we recommend that a combination of PPIA and either GAPDH, ACTB, HPRT and TBP, or appropriate combinations of two or three of these genes, should be employed in future studies, to ensure that results from different studies on different human cancers can be harmonized. This approach will ultimately increase the depth of our understanding of gene expression signatures across human cancers.
TL;DR: Evaluated data indicate that metformin can induce apoptosis in both primary ovarian cancer cells and in SKOV-3 cells, and when met formin was combined with carboplatin or paclitaxel, an increased apoptotic activity was observed, implicating a chemo-adjuvant potential.
Abstract: Ovarian cancer is one of the most common lethal gynecological malignancies world-wide. Despite an initial 70–80 % response rate, most patients relapse within 1–2 years and develop chemo-resistance. Hence, the identification of novel drugs or the repositioning of known drugs to re-sensitize ovarian cancer cells to existing chemotherapy regimens is needed. Here, we evaluated the effect of metformin (an anti-diabetic drug) on ovarian cancer cells, based on its putative effect on other solid tumors. Primary cultures of epithelial ovarian cancer cells established from ascitic fluids of untreated ovarian cancer patients and the SKOV-3 ovarian cancer-derived cell line were used. The respective cells were treated with metformin, carboplatin and paclitaxel alone and its various combinations and their effects, including the ability to induce apoptosis, were examined. Concomitantly, the cells were assessed for the expression of several apoptosis-related mRNAs and proteins using quantitative real time PCR, flowcytometry and Western blotting. We found that metformin induced apoptosis in the ovarian cancer cells tested, and provoked a cell cycle arrest in the G0/G1 and S-phase. Metformin induced apoptosis by down-regulating Bcl-2 and Bcl-xL expression, and up-regulating Bax and Cytochrome c expression. We also found that the apoptosis induction by metformin could be enhanced by a combinatorial use of carboplatin and/or paclitaxel. Our data indicate that metformin can induce apoptosis in both primary ovarian cancer cells and in SKOV-3 cells. When metformin was combined with carboplatin or paclitaxel, an increased apoptotic activity was observed, implicating a chemo-adjuvant potential.
TL;DR: This review will focus on the data reported on molecular classification in the most common tumor types such as breast, colorectal and lung carcinoma, with special emphasis on recent data regarding tumor intrinsic subtypes, and the potential applicability of these new classifications in the clinical routine.
Abstract: Recent technological advances have significantly improved our understanding of tumor biology by means of high-throughput mutation and transcriptome analyses. The application of genomics has revealed the mutational landscape and the specific deregulated pathways in different tumor types. At a transcriptional level, multiple gene expression signatures have been developed to identify biologically distinct subgroups of tumors. By supervised analysis, several prognostic signatures have been generated, some of them being commercially available. However, an unsupervised approach is required to discover a priori unknown molecular subtypes, the so-called intrinsic subtypes. Moreover, an integrative analysis of the molecular events associated with tumor biology has been translated into a better tumor classification. This molecular characterization confers new opportunities for therapeutic strategies in the management of cancer patients. However, the applicability of these new molecular classifications is limited because of several issues such as technological validation and cost. Further comparison with well-established clinical and pathological features is expected to accelerate clinical translation. In this review, we will focus on the data reported on molecular classification in the most common tumor types such as breast, colorectal and lung carcinoma, with special emphasis on recent data regarding tumor intrinsic subtypes. Likewise, we will review the potential applicability of these new classifications in the clinical routine.
TL;DR: The substrate screening indicated that HAUSP may be involved in tumorigenesis, cytoskeletal organization and transport, and chaperone systems and one candidate substrate, TRRAP, was found to physically interact and co-localize withHAUSP.
Abstract: The de-ubiquitinase HAUSP has been reported to exhibit various biological roles implicated in the development of cancer and other pathologies. The dual nature of HAUSP (i.e., oncogenic and tumor suppressive) makes the protein even more versatile. The major aims of this study were to reveal the effect of HAUSP over-expression on the overall proteome and to identify bona fide substrates of HAUSP. In addition, we aimed to unravel the functionality and physiological relevance of the de-ubiquitinating activity of HAUSP on one of its newly identified substrates, TRRAP. An overall proteome analysis was performed after exogenous HAUSP over-expression in HEK293 cells, followed by 2-dimensional gel electrophoresis (2-DE). Interacting proteins were subsequently isolated using immunoprecipitation and 1-dimensional gel electrophoresis (1-DE). Both were followed by tandem MALDI-TOF/TOF mass spectrometry and gene ontology-based analyses. To validate the functionality of one of the identified substrates (TRRAP), Western blotting, immunocytochemistry, immunoprecipitation, in vivo de-ubiquitination, quantitative real-time PCR and luciferase assays were performed. The substrate screening indicated that HAUSP may be involved in tumorigenesis, cytoskeletal organization and transport, and chaperone systems. One candidate substrate, TRRAP, was found to physically interact and co-localize with HAUSP. As TRRAP regulates c-MYC expression, and in order to validate the effect of HAUSP on TRRAP, c-MYC protein and mRNA expression levels were analyzed after exogenous HAUSP over-expression. Both were found to be up-regulated. We also found that c-MYC transactivation increased upon exogenous HAUSP over-expression. By using a luciferase reporter assay, we found that a c-MYC responsive promoter exhibited increased activity, which was subsequently abrogated upon TRRAP knockdown. From our results we conclude that HAUSP may act as an oncogenic protein that can modulate c-MYC expression via TRRAP. Our results provide a new context in which HAUSP may play a role in cancer cell signalling.
TL;DR: The results point at a role of Drosha, Dicer and Ago2 in the development of NSCLC and suggest that Dicer may be implicated in the progression of these tumors to advanced stages.
Abstract: MicroRNAs are evolutionarily conserved non-coding components of the transcriptome that can post-transcriptionally control gene expression. Altered microRNA expression has been found to be a common feature of several cancers, including lung carcinomas. The biogenesis and maturation of microRNAs is known to be mediated by the ribonucleases Drosha, Dicer and Ago2. The purpose of the present study was to investigate the expression and distribution of Drosha, Dicer and Ago2 in human non-small cell lung carcinomas (NSCLC) and to relate the respective expression patterns to clinocopatholical features. We used five human NSCLC-derived cell lines and primary formalin-fixed paraffin-embedded tissue samples from 83 NSCLC patients. Drosha, Dicer and Ago2 mRNA and protein expression levels, and their sub-cellular distributions, were assessed using RT-PCR, Western blotting, immunofluorescence and immunohistochemistry, respectively. We found that Drosha, Dicer and Ago2 were expressed in all the cell lines and primary neoplastic and non-neoplastic tissue samples tested. The intensity of the immunohistochemical staining was found to be significantly lower in stage I tumors compared to normal lung tissues. Dicer expression was found to be significantly higher in stage II compared to stage I tumors, and in stage III compared to stage II and stage I tumors. Our results point at a role of Drosha, Dicer and Ago2 in the development of NSCLC and suggest that Dicer may be implicated in the progression of these tumors to advanced stages.
TL;DR: Investigation of promoter methylation patterns of seven tumor-associated genes in 53 primary HL cases indicates that epigenetic changes frequently occur in both EBV-positive and EBv-negative HL, and the rates of these changes were found to vary according to clinico-pathological parameters.
Abstract: Hodgkin lymphoma (HL) is characterized by the presence of Hodgkin and Reed-Sternberg cells Epstein-Barr virus (EBV) infection is thought to play an important role in the development of HL Although epigenetic alterations, such as aberrant DNA methylation, are known to contribute to the pathogenesis of various malignancies, little is known about such alterations in HL and their putative relationships with EBV infection We investigated promoter methylation patterns of seven tumor-associated genes in 53 primary HL cases using methylation-specific PCR (MS-PCR) Concomitantly, the EBV infection status was assessed using PCR, in situ hybridization and immunohistochemistry The gene promoter hypermethylation frequencies observed were 773 % for P16, 585 % for RASSF1A, 509 % for CDH1, 453 % for DAPK, 434 % for GSTP1, 377 % for SHP1 and 243 % for MGMT SHP1 gene promoter hypermethylation was more frequently observed in patients at extreme ages (ie, ≤ 15 and >54 years) than in adult patients (p = 0006) and in patients with B symptoms (p = 003) Interestingly, most of the analyzed gene promoters were more frequently hypermethylated in EBV-negative than in EBV-positive cases, in particular the DAPK gene promoter (58 % versus 27 %, p = 004) Furthermore, hypermethylation of multiple gene promoters (≥ 3) was encountered more frequently in females than in males (86 % versus 57 %, p = 004), whereas EBV-positive cases were more common among males than females (55 % versus 30 %, p = 002) Our results indicate that epigenetic changes frequently occur in both EBV-positive and EBV-negative HL The rates of these changes were found to vary according to clinico-pathological parameters These observations probably reflect the multitude of factors involved in HL development and the complexity of their interactions with genetic and/or hormonal factors
TL;DR: Molecular imaging with radiolabelled targeted anticancer drugs has great potential for the improvement of personalized cancer care as the non-invasive quantification of drug accumulation in tumours and normal tissues provides understanding of the biodistribution in relation to therapeutic and toxic effects.
Abstract: Molecular imaging has been defined as the visualization, characterization and measurement of biological processes at the molecular and cellular level in humans and other living systems In oncology it enables to visualize (part of) the functional behaviour of tumour cells, in contrast to anatomical imaging that focuses on the size and location of malignant lesions Available molecular imaging techniques include single photon emission computed tomography (SPECT), positron emission tomography (PET) and optical imaging In PET, a radiotracer consisting of a positron emitting radionuclide attached to the biologically active molecule of interest is administrated to the patient Several approaches have been undertaken to use PET for the improvement of personalized cancer care For example, a variety of radiolabelled ligands have been investigated for intratumoural target identification and radiolabelled drugs have been developed for direct visualization of the biodistibution in vivo, including intratumoural therapy uptake First indications of the clinical value of PET for target identification and response prediction in oncology have been reported This new imaging approach is rapidly developing, but uniformity of scanning processes, standardized methods for outcome evaluation and implementation in daily clinical practice are still in progress In this review we discuss the available literature on molecular imaging with PET for personalized targeted treatment strategies Molecular imaging with radiolabelled targeted anticancer drugs has great potential for the improvement of personalized cancer care The non-invasive quantification of drug accumulation in tumours and normal tissues provides understanding of the biodistribution in relation to therapeutic and toxic effects
TL;DR: The results indicate that aberrant SOX11 gene promoter methylation may underlie its down-regulation in GC, and may serve as a biomarker to predict the clinical outcome of GC.
Abstract: Gastric cancer (GC) is the second most common cause of cancer mortality world-wide. In recent years, aberrant SOX11 expression has been observed in various solid and hematopoietic malignancies, including GC. In addition, it has been reported that SOX11 expression may serve as an independent prognostic factor for the survival of GC patients. Here, we assessed the SOX11 gene promoter methylation status in various GC cell lines and primary GC tissues, and evaluated its clinical significance. Five GC cell lines were used to assess SOX11 expression by qRT-PCR. The effect of SOX11 expression restoration after 5-aza-2′-deoxycytidine (5-Aza-dC) treatment on GC growth was evaluated in GC cell line MKN45. Subsequently, 89 paired GC-normal gastric tissues were evaluated for their SOX11 gene promoter methylation status using methylation-specific PCR (MSP), and 20 paired GC-normal gastric tissues were evaluated for their SOX11 expression in relation to SOX11 gene promoter methylation. GC patient survival was assessed by Kaplan-Meier analyses and a Cox proportional hazard model was employed for multivariate analyses. Down-regulation of SOX11 mRNA expression was observed in both GC cell lines and primary GC tissues. MSP revealed hyper-methylation of the SOX11 gene promoter in 55.1 % (49/89) of the primary GC tissues tested and in 7.9 % (7/89) of its corresponding non-malignant tissues. The SOX11 gene promoter methylation status was found to be related to the depth of GC tumor invasion, Borrmann classification and GC differentiation status. Upon 5-Aza-dC treatment, SOX11 expression was found to be up-regulated in MKN45 cells, in conjunction with proliferation inhibition. SOX11 gene promoter hyper-methylation was found to be significantly associated with a poor prognosis and to serve as an independent marker for survival using multivariate Cox regression analysis. Our results indicate that aberrant SOX11 gene promoter methylation may underlie its down-regulation in GC. SOX11 gene promoter hyper-methylation may serve as a biomarker to predict the clinical outcome of GC.
TL;DR: Down-regulated CDK10 expression frequently occurs in breast cancers and correlates with disease progression and poor survival and may serve as a prognostic biomarker for breast cancer.
Abstract: Cyclin-dependent kinase 10 (CDK10) has recently been identified as a tumor suppressor and, concordantly, its encoding gene has frequently been found to be inactivated in various human cancers. Here, we examined the expression status of CDK10 in a panel of primary human breast cancers and evaluated its correlation with clinicopathological parameters and clinical outcome. Western blotting was used to assess CDK10 protein levels in 20 paired breast cancer tissues and adjacent noncancerous tissues. In addition, immunohistochemistry was performed in 128 formalin-fixed, paraffin-embedded tumor tissues. Associations of CDK10 expression with various clinicopathological parameters were evaluated and Kaplan-Meier survival analyses and Cox proportional hazards models were used to estimate its effect on patient survival. We found that CDK10 protein expression was markedly decreased in cancer tissues compared to adjacent noncancerous tissues. Immunohistochemistry revealed decreased CDK10 levels in 65/128 (50.8 %) of the primary breast cancer tissues tested. These decreased levels were found to be significantly associated with lymph node metastasis (P = 0.003), advanced tumor stage (P < 0.001) and unfavorable overall survival (P < 0.001). Furthermore, multivariate analyses indicated that CDK10 expression may serve as an independent prognostic factor for survival (P = 0.001). Down-regulated CDK10 expression frequently occurs in breast cancers and correlates with disease progression and poor survival. CDK10 may serve as a prognostic biomarker for breast cancer.
TL;DR: The data suggest a mechanism by which CT-Cx43 may regulate cell proliferation, which may be instrumental for therapeutic intervention in human breast cancer.
Abstract: Connexin 43 (Cx43) is a widely expressed gap junction protein. It can also regulate various gap-junction independent processes, including cellular proliferation. The latter regulatory functions have been attributed to its carboxy-terminal domain, CT-Cx43. CT-Cx43 has been found to be expressed independent of full-length Cx43 in various cell types. Its nuclear localization has additionally raised the possibility that it may regulate the expression of particular genes, including miRNAs, known play a role in the regulation of cellular proliferation. Here, we set out to uncover the molecular mechanism(s) underlying CT-Cx43 mediated gene (de-)regulation in human breast cancer. Western blotting and quantitative real time PCR were carried to assess the expression of CT-Cx43 and miR-125b in a panel of 60 primary human breast cancer tissues and its paired normal adjacent tissues. In addition, CT-Cx43 was exogenously expressed in the breast cancer-derived cell line MCF-7 and its effect on the expression of miR-125b and its downstream target p53 were evaluated, as well as its effect on cellular proliferation and death using MTT and LDH assays, respectively. We found that CT-Cx43, but not full-length Cx43, was down-regulated in low grade human breast cancers. In addition, we found that the tumor suppressor protein p53 exhibited a decreased expression in the CT-Cx43 down-regulated samples. Interestingly, we found that miR-125b, a negative regulator of p53, exhibited an inverse expression relationship with CT-Cx43 in the breast cancer samples tested. This inverse relationship was confirmed by exogenous expression of CT-Cx43 in MCF-7 cells. In addition, we found that CT-Cx43 up-regulation and subsequent miR-125b down-regulation resulted in a decreased proliferation of MCF-7 cells. Our data suggest a mechanism by which CT-Cx43 may regulate cell proliferation. Targeting of CT-Cx43 and/or miR-125b may be instrumental for therapeutic intervention in human breast cancer.
TL;DR: The results suggest that SAHA may be used as a single-drug treatment option for neuroblastomas with an amplified MYCN gene, and as an adjuvant treatment options for all neuroblastoma.
Abstract: In the past, the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) has been shown to induce apoptosis in several human tumor types, including neuroblastomas. Amplification and over-expression of the MYCN oncogene is a diagnostic hallmark and a poor prognostic indicator in high-risk neuroblastomas. Here, we studied the relationship between MYCN amplification and over-expression and the anti-tumor effect of SAHA to assess whether this drug may serve as a treatment option for high-risk neuroblastomas. Different human neuroblastoma cell lines, over-expressing or not over-expressing MYCN, were used in this study. Targeted knockdown and exogenous over-expression of MYCN were employed to examine correlations between MYCN expression levels and SAHA responses. After various time periods and concentration exposures to the drug, cell viability was measured by MTS assay, and variations in MYCN mRNA and protein levels were assessed by qPCR and Western blotting, respectively. We found that SAHA decreased cell viability in all cell lines tested through apoptosis induction, and that SAHA had a stronger effect on cell lines carrying an amplified MYCN gene. A decrease in MYCN mRNA and protein levels was observed in the SAHA treated cell lines. Subsequent silencing and exogenous over-expression of MYCN changed the proliferation rate of the cells, but did not have any significant impact on the effect of SAHA on the viability of the cells. We also found that SAHA blocked the expression of MYCN and, by doing so, reduced the effects mediated by this protein. Our results suggest that SAHA may be used as a single-drug treatment option for neuroblastomas with an amplified MYCN gene, and as an adjuvant treatment option for all neuroblastomas.
TL;DR: This study provides novel evidence indicating that synergy between the leptin/Ob-Rb/STAT3 signalling pathway and the HER2 receptor protects tamoxifen-treated HER2 over-expressing cells from the inhibitory effect of tamoxIFen through differential regulation of apoptosis-related genes.
Abstract: Tamoxifen is a major treatment modality for estrogen receptor positive breast cancer, but the occurrence of resistance remains a problem. Recently, obesity-related leptin has been found to interfere with tamoxifen in breast cancer MCF-7 cells. In the present study we investigated the effect of leptin on three tamoxifen-treated breast cancer cell types (i.e., MDA-MB-231, MCF-7 and MCF-7/HER2). The effect of tamoxifen/leptin treatment was evaluated using a MTT cell viability assay. mRNA expression was assessed by real time PCR and protein expression by Western blotting. WWOX, Survivin and BCL2 gene promoter activities were evaluated by chromatin immunoprecipitation. Cell viability assays revealed that estrogen receptor negative MDA-MB-231 cells were resistant, that estrogen receptor positive MCF-7 cells were sensitive and that MCF-7/HER2 cells were relatively resistant to tamoxifen, while leptin co-administration ‘rescued’ MCF-7 and, especially, MCF-7/HER2 cells from the anti-proliferative effect of tamoxifen. The cell lines also exhibited a different phosphorylation status of STAT3, a transcription factor that is activated by the obesity related leptin receptor b (Ob-Rb). Most importantly, chromatin immunoprecipitation assays revealed differential STAT3 binding to the anti-apoptotic BCL2 and pro-apoptotic WWOX gene promoters in MCF-7 and MCF-7/HER2 cells, leading to concomitant modifications of its mRNA/protein expression levels, thus providing a selective advantage to HER2 over-expressing MCF-7/HER2 cells after treatment with tamoxifen and tamoxifen plus leptin. Our study provides novel evidence indicating that synergy between the leptin/Ob-Rb/STAT3 signalling pathway and the HER2 receptor protects tamoxifen-treated HER2 over-expressing cells from the inhibitory effect of tamoxifen through differential regulation of apoptosis-related genes.
TL;DR: The various BM metastasis-related molecular changes identified to date may be instrumental for a better diagnosis, prognosis and classification of Rb patients, as well as for the development of novel comprehensive (targeted) therapies.
Abstract: Retinoblastoma (Rb) is a progressive cancer which mainly occurs in children, and which is caused by different genetic or epigenetic alterations that lead to inactivation of both alleles of the RB1 gene. Hereditary and non-hereditary forms of Rb do exist, and the hereditary form is associated with an increased risk of secondary malignancies. Metastasis to distant organs is a critical feature of many tumors, and may be caused by various molecular alterations at different stages. Recognition of these alterations and, thus, insight into the processes underlying the development of metastases may result in novel preventive as well as effective targeted treatment options. Rb is associated with metastases to various organs and tissues, including the bone marrow (BM). Here, we provide an overview of mutations and other molecular changes known to be involved in Rb development and metastasis to the BM. This overview is based on a literature search ranging from 1990 to 2015. The various BM metastasis-related molecular changes identified to date may be instrumental for a better diagnosis, prognosis and classification of Rb patients, as well as for the development of novel comprehensive (targeted) therapies.
TL;DR: A closer investigation of the influence of Ras-mediated signaling pathways on CML progression to blast crisis is warranted to uncover new directions for targeted therapies, particularly in cases that are resistant to current tyrosine kinase inhibitors.
Abstract: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the presence of the BCR-ABL1 oncoprotein in cells with a hematopoietic stem cell (HSC) origin. BCR-ABL1 tyrosine kinase activity leads to constitutive activation of Ras, which in turn acts as a branch point to initiate multiple downstream signaling pathways governing proliferation, self-renewal, differentiation and apoptosis. As aberrant regulation of these cellular processes causes transformation and disease progression particularly in advanced stages of CML, investigation of these signaling pathways may uncover new therapeutic targets for the selective eradication of CML stem cells. Transcription factors play a crucial role in unbalancing the Ras signaling network and have recently been investigated as potential modulators in this regard. In this review, we first briefly summarize the Ras-associated molecular pathways that are involved in the regulation of CML stem cell properties. Next we discuss the relevance of Ras-associated transcription factors as nuclear targets in combination treatment strategies for CML. A closer investigation of the influence of Ras-mediated signaling pathways on CML progression to blast crisis is warranted to uncover new directions for targeted therapies, particularly in cases that are resistant to current tyrosine kinase inhibitors.
TL;DR: Evidence is provided for involvement of the p38 MAPK/NF-κB/IκBα pathway in NDV infection and subsequent induction of apoptosis in ccRCC cells.
Abstract: Newcastle disease virus (NDV) is an oncolytic virus that is known to have a higher preference to cancer cells than to normal cells. It has been proposed that this higher preference may be due to defects in the interferon (IFN) responses of cancer cells. The exact mechanism underlying this process, however, remains to be resolved. In the present study, we examined the antiviral response towards NDV infection of clear cell renal cell carcinoma (ccRCC) cells. ccRCC is associated with mutations of the von Hippel-Lindau tumor suppressor gene VHL, whose protein product is important for eliciting cellular responses to changes in oxygen levels. The most common first line treatment strategy of ccRCC includes IFN. Unfortunately, most ccRCC cases are diagnosed at a late stage and often are resistant to IFN-based therapies. Alternative treatment approaches, including virotherapy using oncolytic viruses, are currently being investigated. The present study was designed to investigate the mechanistic pathways underlying the response of ccRCC cells to oncolytic NDV infection. We found that NDV induces activation of NF-κB in ccRCC cells by inducing phosphorylation and subsequent degradation of IκBα. IκBα was found to be phosphorylated as early as 1 hour post-infection and to result in rapid NF-κB nuclear translocation and activation. Importantly, p38 MAPK phosphorylation was found to occur upstream of the NDV-induced NF-κB activation. Restoration of VHL in ccRCC cells did not result in a reduction of this phosphorylation. A similar phenomenon was also observed in several other cancer-derived cell lines. Our data provide evidence for involvement of the p38 MAPK/NF-κB/IκBα pathway in NDV infection and subsequent induction of apoptosis in ccRCC cells.
TL;DR: Mitochondrial induction by DCA may serve as a radio-sensitizer in non-small cell lung cancer through this mechanism through which it increases the oxygen consumption rate and the cytotoxic death rate.
Abstract: Introduction
Lung cancer is the leading cause of cancer death. Radiation therapy plays a key role in its treatment. Ionizing radiation induces cell death through chromosomal aberrations, which trigger mitotic catastrophe and apoptosis. However, many lung cancer patients show resistance to radiation. Dichloroacetate (DCA) is a small molecule that can promote mitochondrial activation by increasing the influx of pyruvate. Here, we tested whether DCA may increase the sensitivity of non-small cell lung cancer (NSCLC) cells to radiation through this mechanism.
TL;DR: It is found that ATRA treatment modulates a set of genes related to EMT, resulting in distinct gene expression signatures for the LEP or MEP subpopulations, and a third subpopulation within the LM38-LP cell line with stem/progenitor cell characteristics, exhibiting a partial resistance to ATRA.
Abstract: Purpose
Breast cancer is the leading cause of death among women worldwide. The exact role of luminal epithelial (LEP) and myoephitelial (MEP) cells in breast cancer development is as yet unclear, as also how retinoids may affect their behaviour. Here, we set out to evaluate whether retinoids may differentially regulate cell type-specific processes associated with breast cancer development using the bi-cellular LM38-LP murine mammary adenocarcinoma cell line as a model.