BMC - Cancer
Identification of low penetrance alleles for lung cancer: The GEnetic Lung CAncer Predisposition Study (GELCAPS)
Background:
Part of the inherited risk to lung cancer is likely to include common, low risk alleles. The identification of this class of susceptibility is contingent on association-based analyses. We established GEnetic Lung CAncer Predisposition Study (GELCAPS) to collect DNA and clinico-pathological data from a large series of cases and a series of spouse/partner controls, thereby generating a key resource for the identification of low risk alleles.
Methods:
GELCAPS was one of the first genetic epidemiological trials in the UK to be adopted by the National Cancer Research Network (NCRN) onto its portfolio with the participation of over 100 oncology departments specialising in the management of lung cancer.
Results:
Samples from over 5,000 independent lung cancer cases and 2,000 controls have so far been assembled through GELCAPS.
Conclusion:
GELCAPS represents one of the largest datasets of its type in the world capable of informing on the contribution of low penetrance alleles to the development of lung cancer and the influence of genetic variation on outcome. In addition our experience in developing the GELCAPS serves to illustrate how large DNA biobanks for genetic analyses can be rapidly generated within the UK using the NCRN.
Categories: BMC Journals
Differential expression of 12 histone deacetylase (HDAC) genes in astrocytomas and normal brain tissue: class II and IV are hypoexpressed in glioblastomas
Background:
Glioblastoma is the most lethal primary malignant brain tumor. Although considerable progress has been made in the treatment of this aggressive tumor, the clinical outcome for patients remains poor. Histone deacetylases (HDACs) are recognized as promising targets for cancer treatment. In the past several years, HDAC inhibitors (HDACis) have been used as radiosensitizers in glioblastoma treatment. However, no study has demonstrated the status of global HDAC expression in gliomas and its possible correlation to the use of HDACis. The purpose of this study was to evaluate and compare mRNA and protein levels of class I, II and IV of HDACs in low grade and high grade astrocytomas and normal brain tissue and to correlate the findings with the malignancy in astrocytomas.
Methods:
Forty-three microdissected patient tumor samples were evaluated. The histopathologic diagnoses were 20 low-grade gliomas (13 grade I and 7 grade II) and 23 high-grade gliomas (5 grade III and 18 glioblastomas). Eleven normal cerebral tissue samples were also analyzed (54 total samples analyzed). mRNA expression of class I, II, and IV HDACs was studied by quantitative real-time polymerase chain reaction and normalized to the housekeeping gene beta-glucuronidase. Protein levels were evaluated by western blotting.
Results:
We found that mRNA levels of class II and IV HDACs were downregulated in glioblastomas compared to low-grade astrocytomas and normal brain tissue (7 in 8 genes, p
Categories: BMC Journals
Improved therapeutic effectiveness by combining liposomal honokiol with cisplatin in lung cancer model
Background Honokiol is a major bioactive compound extracted from Magnolia. The present study was designed to determine whether liposomal honokiol has the antitumor activity against human lung cancer as well as potentiates the antitumor activity of cisplatin in A549 lung cancer xenograft model, if so, to examine the possible mechanism in the phenomenon.
Methods:
Human A549 lung cancer-bearing nude mice were treated with liposomal honokiol, liposomal honokiol plus DDP or with control groups. Apoptotic cells and vessels were evaluated by fluorescent in situ TUNEL assay and by immunohistochemistry with an antibody reactive to CD31 respectively.
Results:
The present study showed that liposomal honokiol alone resulted in effective suppression of the tumor growth, and that the combined treatment with honokiol plus DDP had the enhanced inhibition of the tumor growth and resulted in a significant increase in life span. The more apparent apoptotic cells in the tumors treated with honokiol plus DDP was found in fluorescent in situ TUNEL assay, compared with the treatment with control groups. In addition, the combination of honokiol and DDP apparently reduced the number of vessels by immunolabeling of CD31 in the tissue sections, compared with control groups.
Conclusions:
In summary, our data suggest that honokiol alone had the antitumor activity against human lung cancer in A549 lung cancer xenograft model, and that the combination of honokiol with DDP can enhance the antitumor 3 activity, and that the enhanced antitumor efficacy in vivo may in part result from the increased induction of the apoptosis and the enhanced inhibition of angiogenesis in the combined treatment. The present findings may be of importance to the further exploration of the potential application of the honokiol alone or the combined approach in the treatment of lung carcinoma.
Categories: BMC Journals
Proteomic analysis identifies MMP-9, DJ-1 and A1BG as overexpressed proteins in pancreatic juice from pancreatic ductal adenocarcinoma patients
Background:
There is an urgent need to discover more sensitive and specific biomarkers to improve early diagnosis and screen high-risk patients for pancreatic ductal adenocarcinoma (PDAC). Pancreatic juice is an ideal specimen for PDAC biomarkers discovery, because it is an exceptionally rich source of proteins released from pancreatic cancer cells.
Methods:
To identify novel potential biomarkers for PDAC from pancreatic juice, we carried out difference gel electrophoresis (DIGE) and tandem mass spectrometry (MSMS) to compare the pancreatic juice profiling from 9 PDAC patients and 9 cancer-free controls. Of the identified differently expressed proteins, three up-regulated proteins in pancreatic cancer juice, matrix metalloproteinase-9 (MMP-9), oncogene DJ1 (DJ-1) and alpha-1B-glycoprotein precursor (A1BG), were selected for validation by Western blot and immunohistochemistry. Serum MMP-9 levels were also detected by enzyme linked immunosorbent assay (ELISA).
Results:
Fourteen proteins were up-regulated and ten proteins were down-regulated in cancerous pancreatic juice compared with cancer-free controls. Increased MMP-9, DJ-1 and A1BG expression in cancerous pancreatic juice were confirmed by Western blot. Immunohistochemical study showed MMP-9, DJ-1 and A1BG positively expressed in 82.4%, 72.5% and 86.3% of pancreatic cancer tissues, significantly higher than that in normal pancreas tissues. Up-regulation of DJ-1 was associated with better differentiation (P
Categories: BMC Journals
Establishing an in vivo model of canine prostate carcinoma using the new cell line CT1258.
Background:
Prostate cancer is a frequent finding in man. In dogs, malignant disease of the prostate is also of clinical relevance, although it is a less common diagnosis. Even though there are numerous differences in origin and development of the disease, man and dog share many similarities in the pathological presentation. For this reason, the dog might be a useful animal model for prostate malignancies in man.
Although prostate cancer is of great importance in veterinary medicine as well as in comparative medicine, there are only few cell lines available. Thus, it was the aim of the present study to determine whether the formerly established prostate carcinoma cell line CT1258 is a suitable tool for in vivo testing, and to distinguish the growth pattern of the induced tumours.
Methods:
For characterisation of the in vivo behaviour of the in vitro established canine prostate carcinoma cell line CT1258, cells were inoculated in 19 NOD.CB17-PrkdcScid/J (in the following: NOD-Scid) mice, either subcutaneously or intraperitoneally. After sacrifice, the obtained specimens were examined histologically and compared to the pattern of the original tumour in the donor.
Cytogenetic investigation was performed.
Results:
The cell line CT 1258 not only showed to be highly tumourigenic after subcutaneous as well as intraperitoneal inoculation, but also mimicked the behaviour of the original tumour.
Conclusion:
Tumours induced by inoculation of the cell line CT1258 resemble the situation in naturally occurring prostate carcinoma in the dog, and thus could be used as in vivo model for future studies.
Categories: BMC Journals
Identification of a novel CHEK2 variant and assessment of its contribution to the risk of breast cancer in French Canadian women
Background:
BRCA1 and BRCA2 account for the majority of the known familial breast cancer risk, however, the impact of other cancer susceptibility genes largely remains to be elucidated. Checkpoint Kinase 2 (CHEK2) is an important signal transducer of cellular responses to DNA damage, whose defects have been associated with an increase in breast cancer risk. Previous studies have identified low penetrance CHEK2 alleles such as 1100delC and I157T, as well as variants such as S428F in the Ashkenazi Jewish population and IVS2 + 1G>A in the Polish population. No founder allele has been specifically identified in the French Canadian population.
Methods:
The 14 coding exons of CHEK2 were fully sequenced for variant alleles in a panel of 25 affected French Canadian women and 25 healthy controls. Two variants were identified of which one novel variant was further screened for in an additional panel of 667 breast cancer patients and 6548 healthy controls. Additional genotyping was conducted using allele specific PCR and a restriction digest assay. Significance of amino acid substitutions were deduced by employing comparative analysis techniques.
Results:
Two variants were identified: the previously reported silent substitution 252A>G (E84E) and the novel missense variant, 1217G>A (R406H). No significant difference in allele distribution between French Canadian women with breast cancer and healthy controls was observed (3/692, 0.43% vs. 22/6573, 0.33%, respectively, P = 0.73).
Conclusion:
The novel CHEK2 missense variant identified in this study, R406H, is unlikely to contribute to breast cancer risk in French Canadian women.
Categories: BMC Journals
DNA methylation patterns in bladder cancer and washing cell sediments: a perspective for tumor recurrence detection
Background:
Epigenetic alterations are a hallmark of human cancer. In this study, we aimed to investigate whether aberrant DNA methylation of cancer-associated genes is related to urinary bladder cancer recurrence.
Methods:
A set of 4 genes, including CDH1 (E-cadherin), SFN (stratifin), RARB (retinoic acid receptor, beta) and RASSF1A (Ras association - RalGDS/AF-6 - domain family 1), had their methylation patterns evaluated by MSP (Methylation-Specific Polymerase Chain Reaction) analysis in 49 fresh urinary bladder carcinoma tissues (including 14 cases paired with adjacent normal bladder epithelium, 3 squamous cell carcinomas and 2 adenocarcinomas) and 24 cell sediment samples from bladder washings of patients classified as cancer-free by cytological analysis (control group). A third set of samples included 39 archived tumor fragments and 23 matched washouts from 20 urinary bladder cancer patients in post-surgical monitoring. After genomic DNA isolation and sodium bisulfite modification, methylation patterns were determined and correlated with standard clinico-histopathological parameters.
Results:
CDH1 and SFN genes were methylated at high frequencies in bladder cancer as well as in paired normal adjacent tissue and exfoliated cells from cancer-free patients. Although no statistically significant differences were found between RARB and RASSF1A methylation and the clinical and histopathological parameters in bladder cancer, a sensitivity of 95% and a specificity of 71% were observed for RARB methylation (Fisher's Exact test (p0.0001; OR = 48.89) and, 58% and 17% (p0.05; OR = 0.29) for RASSF1A gene, respectively, in relation to the control group.
Conclusion:
Indistinct DNA hypermethylation of CDH1 and SFN genes between tumoral and normal urinary bladder samples suggests that these epigenetic features are not suitable biomarkers for urinary bladder cancer. However, RARB and RASSF1A gene methylation appears to be an initial event in urinary bladder carcinogenesis and should be considered as defining a panel of differentially methylated genes in this neoplasia in order to maximize the diagnostic coverage of epigenetic markers, especially in studies aiming at early recurrence detection.
Categories: BMC Journals
Similar reductions in the risk of human colon cancer by selective and nonselective cyclooxygenase-2 (COX-2) inhibitors
Background:
Epidemiologic and laboratory investigations suggest that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) have chemopreventive effects against colon cancer perhaps due at least in part to their activity against cyclooxygenase-2 (COX-2), the rate-limiting enzyme of the prostaglandin cascade.
Methods:
We conducted a case control study of colon cancer designed to compare effects of selective and non-selective COX-2 inhibitors. A total of 326 incident colon cancer patients were ascertained from the James Cancer Hospital, Columbus, Ohio, during 2003-2004 and compared with 652 controls with no history of cancer and matched to the cases at a 2:1 ratio on age, race, and county of residence. Data on the past and current use of prescription and over the counter medications and colon cancer risk factors were ascertained using a standardized risk factor questionnaire. Effects of COX-2 inhibiting agents were quantified by calculating odds ratios (OR) and 95% confidence intervals.
Results:
Results showed significant risk reductions for selective COX-2 inhibitors (OR=0.33, 95% CI=0.16-0.59), regular aspirin (OR=0.33, 95% CI = 0.20-0.56), and ibuprofen or naproxen (0.28, 95% CI=0.15-0.54). Acetaminophen, a compound with negligible COX-2 activity and low dose aspirin (81 mg) produced no significant changes in the risk of colon cancer.
Conclusions:
These results suggest that both non-selective and selective COX-2 inhibitors produce significant reductions in the risk of colon cancer, underscoring their strong potential for colon cancer chemoprevention.
Categories: BMC Journals
National Mesothelioma Virtual Bank: a standard based biospecimen and clinical data resource to enhance translational research
Background:
Advances in translational research have led to the need for well characterized biospecimens for research. The National Mesothelioma Virtual Bank (NMVB) is an initiative which collects annotated datasets relevant to human mesothelioma to develop an enterprise biospecimen resource to fulfill researchers' need.
Methods:
The NMVB architecture is based on three major components: (a) common data elements (based on CAP protocol and NAACCR standards), (b) clinical and epidemiologic data annotation, and (c) data query tools. These tools work interoperably to standardize the entire process of annotation. The NMVB tool is based upon the caTISSUE Clinical Annotation Engine (CAE), developed by the University of Pittsburgh in cooperation with the Cancer Biomedical Informatics GridTM (caBIGTM, see http://cabig.nci.nih.gov). This application provides a web-based system for annotating, importing and searching mesothelioma cases. The underlying information model is constructed utilizing Unified Modeling Language (UML) class diagrams, hierarchical relationships and Enterprise Architect (EA) software.
Result: The database provides researchers real-time access to richly annotated specimens and integral information related to mesothelioma. The data disclosed are tightly regulated depending upon users' authorization and depending on the participating institute that is amenable to the local IRB and regulation committee reviews.
Conclusion:
The NMVB currently has over 600 annotated cases available for researchers that include paraffin embedded tissues, tissue microarrays, serum and genomic DNA. The NMVB is a virtual biospecimen registry with robust translational biomedical informatics support to facilitate basic science, clinical, and translational research. Furthermore, it protects patient privacy by disclosing only de-identified datasets to assure that biospecimens can be made accessible to researchers.
Categories: BMC Journals
Lymphotoxin-alpha polymorphisms and presence of cancer in 1,536 consecutive autopsy cases
Background:
Lymphotoxin-alpha (LTA) is a pro-inflammatory cytokine with anti-tumor activity.
The objective of this study was to determine whether LTA polymorphisms influence the presence of cancer.
Methods:
LTA polymorphisms C804A (rs1041981, T60N) and T495C (rs2229094, C13R) were determined in 1,536 consecutive autopsy cases and were registered in the Japanese single-nucleotide polymorphisms (SNPs) for geriatric research (JG-SNP) Internet database. Tumors were systematically reviewed, pathologically confirmed, and assessed in relation to LTA genotype.
Results:
The study population consisted of 827 males and 709 females, with a mean age of 80 years. Altogether, we studied 606 subjects without cancer and 930 subjects with cancer of the stomach (n = 183), lung (n = 164), colon or rectum (n = 143), or other sites. The presence of cancer was higher in males than in females. The C804A and T495C polymorphisms were associated with cancer in males (CA + AA: CC, adjusted OR = 0.72, 95% CI = 0.53 - 0.99; TC + CC: TT, adjusted OR = 1.45, 95% CI = 1.04 - 2.02; respectively) but not in females. In males, the C804A polymorphism was associated with lung cancer (CA + AA: CC, adjusted OR = 0.60, 95% CI = 0.37 - 0.97), whereas the T495C polymorphism was associated with gastric cancer (TC + CC: TT, adjusted OR = 1.68, 95% CI = 1.06 - 2.65).
Conclusions:
We found some evidence of an association between LTA polymorphisms and cancer risk in elderly Japanese men. Further studies in larger populations should examine this hypothesis.
Categories: BMC Journals
Potential value of PTEN in predicting cetuximab response in colorectal cancer. An exploratory study.
Background:
The epidermal growth factor receptor (EGFR) is over-expressed in 70-75% of colorectal adenocarcinomas (CRC). The anti-EGFR monoclonal antibody cetuximab has been approved for the treatment of metastatic CRC, however tumor response to cetuximab has not been found to be associated with EGFR over-expression by immunohistochemistry (IHC). The aim of this study was to explore EGFR and the downstream effector phosphatase and tensin homologue deleted on chromosome 10 (PTEN) as potential predictors of response to cetuximab.
Methods:
CRC patients treated with cetuximab by the Hellenic Cooperative Oncology group, whose formalin-fixed paraffin-embedded tumor tissue was available, were included. Tissue was tested for EGFR and PTEN by IHC and fluorescence in situ hybridization (FISH).
Results:
Eighty-eight patients were identified and 72 were included based on the availability of tissue blocks with adequate material for analysis on them. All patients, except one, received cetuximab in combination with chemotherapy. Median follow-up was 53 months from diagnosis and 17 months from cetuximab initiation. At the time of the analysis 53% of the patients had died. Best response was complete response in one and partial response in 23 patients. In 16 patients disease stabilized. Normal PTEN gene amplification was associated with more responses to cetuximab and longer time to progression (p=0.042).
Conclusions:
PTEN could be one of the molecular determinants of cetuximab response. Due to the heterogeneity of the population and the retrospective nature of the study, our results are hypothesis generating and should be approached with caution. Further prospective studies are needed to validate this finding.
Categories: BMC Journals
Prognostic relevance of Centromere protein H expression in esophageal carcinoma.
Background:
Many kinetochore proteins have been shown to be associated with human cancers. The aim of the present study was to clarify the expression of Centromere protein H (CENP-H), one of the fundamental components of the human active kinetochore, in esophageal carcinoma and its correlation with clinicopathological features.
Methods:
We examined the expression of CENP-H in immortalized esophageal epithelial cells as well as in esophageal carcinoma cells, and in 12 cases of esophageal carcinoma tissues and the paired normal esophageal tissues by RT-PCR and Western blot analysis. In addition, we analyzed CENP-H protein expression in 177 clinicopathologically characterized esophageal carcinoma cases by immunohistochemistry. Statistical analyses were applied to test for prognostic and diagnostic associations.
Results:
The level of CENP-H mRNA and protein were higher in the immortalized cells, cancer cell lines and most cancer tissues than in normal control tissues. Immunohistochemistry showed that CENP-H was expressed in 127 of 171 ESCC cases (74.3%) and in 3 of 6 esophageal adenocarcinoma cases (50%). Statistical analysis of ESCC cases showed that there was a significant difference of CENP-H expression in patients categorized according to gender (P=0.013), stage (P = 0.023) and T classification (P = 0.019). Patients with lower CENP-H expression had longer overall survival time than those with higher CENP-H expression. Multivariate analysis suggested that CENP-H expression was an independent prognostic marker for esophageal carcinoma patients. A prognostic value of CENP-H was also found in the subgroup of T3-T4 and N0 tumor classification.
Conclusions:
Our results suggest that CENP-H protein is a valuable marker of esophageal carcinoma progression. CENP-H might be used as a valuable prognostic marker for esophageal carcinoma patients.
Categories: BMC Journals
EGFR and HER2 expression in primary cervical cancers and corresponding lymph node metastases: Implications for targeted radiotherapy
Background:
Proteins overexpressed on the surface of tumor cells can be selectively targeted. Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are among the most often targeted proteins. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target for imaging in nuclear medicine and for various forms of therapy. So far, the expression of EGFR and HER2 has only been determined in primary cervical cancers, and we have not found published data regarding the receptor status in corresponding metastatic lesions. The goal of this study was to evaluate whether any of these receptors are suitable as target for clinical diagnosis and therapy.
Methods:
Expression of EGFR and HER2 was investigated immunohistochemically in both lymph node metastases and corresponding primary cervical cancers (n=53). HER2 and EGFR expression was scored using HercepTest criteria (0, 1+, 2+ or 3+).
Results:
EGFR overexpression (2+ or 3+) was found in 64% (35/53) of the primary cervical tumors and 60% (32/53) of the corresponding lymph node metastases. There was a good concordance between the primary tumors and the paired metastases regarding EGFR expression. Only four patients who had 2+ or 3+ in the primary tumors changed to 0 or 1+ in lymph node metastases, and another two cases changed the other way around. None of the primary tumors or the lymph node metastases expressed HER2 protein.
Conclusions:
The EGFR expression seems to be common and stable during cervical cancer metastasis, which is encouraging for testing of EGFR targeted radiotherapy. HER2 appears to be of poor interest as a potential target in the treatment of cervical cancer.
Categories: BMC Journals
Tetratricopeptide repeat domain 9A is an interacting protein for tropomyosin Tm5NM-1
Background:
Tetratricopeptide repeat domain 9A (TTC9A) protein is a recently identified protein which contains three tetratricopeptide repeats (TPRs) on its C-terminus. In our previous studies, we have shown that TTC9A was a hormonally-regulated gene in breast cancer cells. In this study, we found that TTC9A was over-expressed in breast cancer tissues compared to the adjacent controls (P
Categories: BMC Journals
Association of TMPRSS2-ERG gene fusion with clinical characteristics and outcomes: Results from a population-based study of prostate cancer.
Background:
The presence of the TMPRSS2-ERG fusion gene in prostate tumors has recently been associated with an aggressive phenotype, as well as recurrence and death from prostate cancer. These associations suggest the hypothesis that the gene fusion may be used as a prognostic indicator for prostate cancer.
Methods:
In this study, fluorescent in situ hybridization (FISH) assays were used to assess TMPRSS2-ERG fusion status in a group of 214 prostate cancer cases from two population-based studies. The FISH assays were designed to detect both fusion type (deletion vs. translocation) and the number of fusion copies (single vs. multiple). Genotyping of four ERG and one TMPRSS2 SNPs using germline DNA was also performed in a sample of the cases (n=127).
Results:
Of the 214 tumors scored for the TMPRSS2-ERG fusion, 64.5% were negative and 35.5% were positive for the fusion. Cases with the TMPRSS2-ERG fusion did not exhibit reduced prostate cancer survival (HR=0.92, 95% CI=0.22-3.93), nor was there a significant difference in cause-specific survival when stratifying by translocation or deletion (HR=0.84, 95% CI=0.23-3.12) or by the number of retained fusion copies (HR=1.22, 95% CI=0.45-3.34). However, evidence for reduced prostate cancer-specific survival was apparent in those cases whose tumor had multiple copies of the fusion. The variant T allele of the TMPRSS2 SNP, rs12329760, was positively associated with TMPRSS2-ERG fusion by translocation (p=0.05) and with multiple copies of the gene fusion (p=0.03).
Conclusion:
If replicated, the results presented here may provide insight into the mechanism by which the TMPRSS2-ERG gene fusion arises and also contribute to diagnostic evaluations for determining the subset of men who will go on to develop metastatic prostate cancer.
Categories: BMC Journals
Cigarette Smoke Induces Endoplasmic Reticulum Stress and the Unfolded Protein Response in Normal and Malignant Human Lung Cells
Background:
Although lung cancer is among the few malignancies for which we know the primary etiological agent (i.e., cigarette smoke), a precise understanding of the temporal sequence of events that drive tumor progression remains elusive. In addition to finding that cigarette smoke (CS) impacts the functioning of key pathways with significant roles in redox homeostasis, xenobiotic detoxification, cell cycle control, and endoplasmic reticulum (ER) functioning, our data highlighted a defensive role for the unfolded protein response (UPR) program. The UPR promotes cell survival by reducing the accumulation of aberrantly folded proteins through translation arrest, production of chaperone proteins, and increased degradation. Importance of the UPR in maintaining tissue health is evidenced by the fact that a chronic increase in defective protein structures plays a pathogenic role in diabetes, cardiovascular disease, Alzheimer's and Parkinson's syndromes, and cancer.
Methods:
Gene and protein expression changes in CS exposed human cell cultures were monitored by high-density microarrays and Western blot analysis. Tissue arrays containing samples from 110 lung cancers were probed with antibodies to proteins of interest using immunohistochemistry.
Results:
We show that: 1) CS induces ER stress and activates components of the UPR; 2) reactive species in CS that promote oxidative stress are primarily responsible for UPR activation; 3) CS exposure results in increased expression of several genes with significant roles in attenuating oxidative stress; and 4) several major UPR regulators are increased either in expression (i.e., BiP and eIF2alpha) or phosphorylation (i.e., phospho-eIF2alpha) in a majority of human lung cancers.
Conclusions:
These data indicate that chronic ER stress and recruitment of one or more UPR effector arms upon exposure to CS may play a pivotal role in the etiology or progression of lung cancers, and that phospho-eIF2alpha and BiP may have diagnostic and/or therapeutic potential. Furthermore, we speculate that upregulation of UPR regulators (in particular BiP) may provide a pro-survival advantage by increasing resistance to cytotoxic stresses such as hypoxia and chemotherapeutic drugs, and that UPR induction is a potential mechanism that could be attenuated or reversed resulting in a more efficacious treatment strategy for lung cancer.
Categories: BMC Journals
Imagable 4T1 model for the study of late stage breast cancer
Background:
The 4T1 mouse mammary tumor cell line is one of only a few breast cancer models with the capacity to metastasize efficiently to sites affected in human breast cancer. Here we describe two 4T1 cell lines modified to facilitate analysis of tumor growth and metastasis and evaluation of gene function in vivo. New information regarding the involvement of innate and acquired immunity in metastasis and other characteristics of the model relevant to its use in the study of late stage breast cancer are reported.
Methods:
The lines were engineered for stable expression of firefly luciferase to allow tracking and quantitation of the cells in vivo. Biophotonic imaging was used to characterize growth and metastasis of the lines in vivo and an improved gene expression approach was used to characterize the basis for the metastatic phenotype that was observed.
Results:
Growth of cells at the primary site was biphasic with metastasis detected during the second growth phase 5-6 weeks after introduction of the cells. Regression of growth, which occurred in weeks 3-4, was associated with extensive necrosis and infiltration of leukocytes. Biphasic tumor growth did not occur in BALB/c SCID mice indicating involvement of an acquired immune response in the effect. Hematopoiesis in spleen and liver and elevated levels of circulating leukocytes were observed at week 2 and increased progressively until death at week 6-8. Gene expression analysis revealed an association of several secreted factors including colony stimulatory factors, cytokines and chemokines, acute phase proteins, angiogenesis factors and ECM modifying proteins with the 4T1 metastatic phenotype. Signaling pathways likely to be responsible for production of these factors were also identified.
Conclusions:
The production of factors that stimulate angiogenesis and ECM modification and induce hematopoiesis, recruitment and activation of leukocytes suggest that 4T1 tumor cells play a more direct role than previously appreciated in orchestrating changes in the tumor environment conducive to tumor cell dissemination and metastasis. The new cell lines will greatly facilitate the study of late stage breast and preclinical assessment of cancer drugs and other therapeutics particularly those targeting immune system effects on tumor metastasis.
Categories: BMC Journals
A high-throughput and sensitive method to measure Global DNA Methylation: Application in Lung Cancer
Background:
Genome-wide changes in DNA methylation are an epigenetic phenomenon that can lead to the development of disease. The study of global DNA methylation utilizes technology that requires both expensive equipment and highly specialized skill sets.
Methods:
We have designed and developed an assay, CpGlobal, which is easy-to-use, does not utilize PCR, radioactivity and expensive equipment. CpGlobal utilizes methyl-sensitive restriction enzymes, HRP Neutravidin to detect the biotinylated nucleotides incorporated in an end-fill reaction and a luminometer to measure the chemiluminescence. The assay shows high accuracy and reproducibility in measuring global DNA methylation. Furthermore, CpGlobal correlates significantly with High Performance Capillary Electrophoresis (HPCE), a gold standard technology. We have applied the technology to understand the role of global DNA methylation in the natural history of lung cancer. World-wide, it is the leading cause of death attributed to any cancer. The survival rate is 15% over 5 years due to the lack of any clinical symptoms until the disease has progressed to a stage where cure is limited.
Results:
Through the use of cell lines and paired normal/tumor samples from patients with non-small cell lung cancer (NSCLC) we show that global DNA hypomethylation is highly associated with the progression of the tumor. In addition, the results provide the first indication that the normal part of the lung from a cancer patient has already experienced a loss of methylation compared to a normal individual.
Conclusions:
By detecting these changes in global DNA methylation, CpGlobal may have a role as a barometer for the onset and development of lung cancer.
Categories: BMC Journals
Esophageal cancer risk by type of alcohol drinking and smoking: a case-control study in Spain
Background:
The effect of tobacco smoking and alcohol drinking on esophageal cancer (EC) has never been explored in Spain where black tobacco and wine consumptions are quite prevalent. We estimated the independent effect of different alcoholic beverages and type of tobacco smoking on the risk of EC and its main histological cell type (squamous cell carcinoma) in a hospital-based case-control study in a Mediterranean area of Spain.
Methods:
We only included incident cases with histologically confirmed EC (n=202). Controls were frequency-matched to cases by age, sex and province (n=455). Information on risk factors was elicited by trained interviewers using structured questionnaires. Multiple logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals (CI).
Results:
Alcohol drinking and tobacco smoking were strong and independent risk factors for esophageal cancer. Alcohol was a potent risk factor with a clear dose-response relationship, particularly for esophageal squamous-cell cancer. Compared to never-drinkers, the risk for heaviest drinkers ([greater than or equal to]75 g/day of pure ethanol) was 7.65 (95%CI, 3.16-18.49); and compared with never-smokers, the risk for heaviest smokers ([greater than or equal to]30 cigarettes/day) was 5.07 (95%CI, 2.06-12.47). A low consumption of only wine and/or beer (1-24g/d) did not increase the risk whereas a strong positive trend was observed for all types of alcoholic beverages that included any combination of hard liquors with beer and/or wine (p-trend
Categories: BMC Journals
Prognostic value analysis of urokinase-type plasminogen activator receptor in oral squamous cell carcinoma: an immunohistochemical study
Background:
Oral squamous cell carcinoma (OSCC) represents the most common oral malignancy. Despite recent advances in therapy, up to 50% of the cases have relapse and/or metastasis. There is therefore a strong need for the identification of new biological markers able to predict the clinical behaviour of these lesions in order to improve quality of life and overall survival. Among tumour progression biomarkers, already known for their involvement in other neoplasia, a crucial role is ascribed to the urokinase-type plasminogen activator receptor (uPAR), which plays a multiple role in extracellular proteolysis, cell migration and tissue remodelling not only as a receptor for the zymogen pro-uPA but also as a component for cell adhesion and as a chemoattractant. The purpose of this study was to gain information on the expression of uPAR in OSCC and to verify whether this molecule can have a role as a prognostic/predictive marker for this neoplasia.
Methods:
In a retrospective study, a cohort of 189 OSCC patients was investigated for uPAR expression and its cellular localization by immunohistochemistry. As standard controls, 8 normal oral mucosal tissues free of malignancy, obtained from patients with no evidence or history of oral cavity tumours, were similarly investigated. After grouping for uPAR expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G), tumour size, recurrence, TNM staging and overall survival rate.
Results:
In our immunohistochemical study, 74 cases (39.1%) of OSCC showed a mostly cytoplasmic positivity for uPAR, whereas 115 were negative. uPAR expression correlated with tumour differentiation grade and prognosis: percentage of positive cases was the greatest in G3 (70.4%) and patients positives for uPAR expression had an expectation of life lower than those for uPAR negatives.
Conclusion:
The results obtained in this study suggest a role of uPAR as a potential biomarker useful to identify higher risk subgroups of OSCC patients.
Categories: BMC Journals
