Differences in gene expression profiles and carcinogenesis pathways between colon and rectal cancer

Identification of Key Genes in Fetal Gut Development at Single-Cell Level by Exploiting Machine Learning Techniques

The study of fetal gut development is critical due to its substantial influence on immediate neonatal and long-term adult health. Current research largely focuses on microbiome colonization, gut immunity, and barrier function, alongside the impact of external factors on these phenomena. Limited research has been dedicated to the categorization of developing fetal gut cells. Our study aimed to enhance our understanding of fetal gut development by employing advanced machine-learning techniques on single-cell sequencing data. This dataset consisted of 62,849 samples, each characterized by 33,694 distinct gene features. Four feature ranking algorithms were utilized to sort features according to their significance, resulting in four feature lists. Then, these lists were fed into an incremental feature selection method to extract essential genes, classification rules, and build efficient classifiers. Several important genes were recognized by multiple feature ranking algorithms, such as FGG, MDK, RBP1, RBP2, IGFBP7, and SPON2. These features were key in differentiating specific developing intestinal cells, including epithelial, immune, mesenchymal, and vasculature cells of the colon, duo jejunum, and ileum cells. The classification rules showed special gene expression patterns on some intestinal cell types and the efficient classifiers can be useful tools for identifying intestinal cells.

Survival outcomes after synchronous para-aortic lymph node metastasis in colorectal cancer: A systematic review

BACKGROUND

Synchronous para-aortic lymph node metastasis (PALNM) in colorectal cancer (CRC) is a relatively rare clinical entity. There is a lack of consensus on management of these patients, and the role of para-aortic lymph node dissection (PALND) remains controversial. This systematic review aims to describe the survival outcomes in colorectal cancer with synchronous PALNM when lymph node dissection is performed.

METHODS

A systematic review of Pubmed, Embase and Web of Science databases for PALND in CRC was performed. Studies including patients with synchronous PALNM undergoing resection with curative intent, published from the year 2000 onwards, were included.

RESULTS

Twelve retrospective studies were included. Four studies reported survival outcomes for rectal cancer, two for colon cancer and six as colorectal. Survival outcomes for 356 patients were included. Average 5-year overall survival (OS) was 22.4%, 33.9% and 37.7% in the rectal, colon and colorectal groups respectively. Three year OS in the groups was 53.6%, 46.2% and 65.7%.

CONCLUSION

There remains a lack of quality data to confidently make recommendations regarding the management of synchronous PALNM in colon and rectal cancer cohorts. Retrospective data suggests a benefit in highly selective cohorts and therefore a case-by-case evaluation remains the standard of care.

ADAMTS6: Emerging roles in cardiovascular, musculoskeletal and cancer biology

ADAMTS family members control mammalian development and disease, primarily through their function as proteases, by regulation of extracellular matrix composition. Until recently, ADAMTS6 was known as one of the orphan proteinases of the nineteen-member family with a relatively unknown expression pattern and function. Emerging focus on this enzyme has started to uncover these unknowns and revealed a vast importance and requirement of ADAMTS6 in cardiovascular and musculoskeletal development. In addition, ADAMTS6 has been linked to numerous disease settings including several types of cancer. This review summarizes the necessity of ADAMTS6 during development, its role in disease and requirement for essential prospective studies to fully realize its biological implications and potential for therapeutic intervention.

Microsatellite instability in rectal cancer: what does it mean? A study of two randomized trials and a systematic review of the literature

Currently, compelling evidence illustrates the significance of determining microsatellite instability (MSI) in colorectal cancer (CRC). The association of MSI with proximal CRC is well established, however, its implications in patients with rectal cancer remain undefined. We therefore aimed to determine the role of MSI with respect to incidence and outcome in patients with rectal cancer, by the examination of patients from two prospective phase III trials: TME trial and PROCTOR-SCRIPT trial (n=1250). No differences in terms of overall survival (HR 1.00, 95%CI 0.69-1.47) and disease-free survival (HR 1.00, 95%CI 0.68-1.45) were observed in patients with MSI compared to microsatellite stable (MSS) rectal cancer. In addition, we performed a literature review to evaluate the overall prevalence, the effect on survival and the response to neo-adjuvant treatment in patients with MSI rectal cancer compared with MSS rectal cancer. The total number of MSI cases in the included studies (including our own) was 1220 (out of 16526 rectal cancer patients), with an overall prevalence of 6.7% (SE 1.19%). Both for overall survival as for disease-free survival there was no impact of MSI status on prognosis (HR 1.00, 95%CI 0.77-1.29 and HR 0.86, 95% CI 0.60-1.22, respectively). The risk ratio for downstaging and pCR showed also no impact of MSI status (RR 1.15, 95% CI 0.86-1.55 and RR 0.81, 95% CI 0.54-1.22 respectively). In conclusion, rectal cancer patients with MSI form a distinct and rare subcategory, however, there is no prognostic effect of MSI in rectal cancer patients.

Correlation of cholesteryl ester metabolism to pathogenesis, progression and disparities in colorectal Cancer

Background

Colorectal cancer (CRC) is one of the most common cancers worldwide characterized by disparities in age, gender, race and anatomic sites. The mechanism underlying pathogenesis, progression and disparities of CRC remains unclear. This study aims to reveal the association of expression levels of enzymes related to cholesteryl ester (CE) metabolism with pathogenesis, progression and disparities of CRC.

Methods

The differences in gene expression levels were analyzed for enzymes in CE synthesis (acyl CoA: cholesterol acyltransferase 1 and 2, ACAT1, and ACAT2), and in CE hydrolysis (neutral cholesterol ester hydrolase, NCEH1 and lysosomal acid lipase, LAL) on TNMplot platform between CRC and normal colorectal tissues (NCT) in a large cohort. The differences in protein expression levels for these enzymes were determined by Immunochemistry (IHC) performed on tissue microarray containing 96 pairs of CRC and benign colorectal tissues (BCT) from different patient populations. The expression level represented as IHC score of each enzyme was compared between CRC and BCT in entire population and populations stratified by race, gender and anatomic sites. Student’s t-test, Fisher exact test and ANOVA were used for data analysis. Significant p value was set at P<0.05.

Results

The gene expression level of ACAT1 was significantly lower in CRC than in NCT (P = 2.15e-119). The gene expression level of ACAT2 was not statistically different between CRC and NCT. The gene expression level of LIPA (encoding LAL) was significantly higher in CRC than in NCT (P = 2.01e-14). No data was found for the gene expression level of NCEH1. The IHC score of ACAT1was significantly lower in CRC than in BCT in all studied populations and in sub site of colon, but not in that of rectum. The IHC score of ACAT2 was not statistically different between CRC and BCT. IHC score of NCEH1 was significantly higher in CRC than in BCT only in African American (AA) population. The IHC score of LAL was significantly higher in CRC than in BCT in all studied populations and in all sub sites. In addition, decreased ACAT1 in CRC significantly correlated to progression of CRC: the lower IHC score of ACAT1, the more advanced clinical stage of CRC will be.

Conclusions

This study revealed that altered expression levels in enzymes related to CE metabolism highly correlate to the pathogenesis, clinical progression and disparities of CRC. The results will add revenue in elucidating mechanisms underlying progression of CRC, and shed light on seeking biomarkers and exploring therapeutic targets for CRC in a new direction.

Predicted Vitamin D Status and Colorectal Cancer Incidence in the Black Women's Health Study

BACKGROUND

Observational studies, mostly among White populations, suggest that low vitamin D levels increase colorectal cancer risk. African Americans, who are disproportionately burdened by colorectal cancer, often have lower vitamin D levels compared with other populations.

METHODS

We assessed predicted vitamin D score in relation to colorectal cancer among 49,534 participants in the Black Women's Health Study, a cohort of African American women followed from 1995 to 2017 through biennial questionnaires. We derived predicted vitamin D scores at each questionnaire cycle for all participants using a previously validated prediction model based on actual 25-hydroxyvitamin D values from a subset of participants. We calculated cumulative average predicted vitamin D score at every cycle by averaging scores from cycles up to and including that cycle. Using Cox proportional hazards regression, we estimated hazard ratios (HR) and 95% confidence intervals (CI) for colorectal cancer incidence according to predicted score quartiles.

RESULTS

Over follow-up, 488 incident colorectal cancers occurred. Compared with women in the highest quartile of predicted vitamin D score, those in the lowest had an estimated 41% (HR = 1.41; 95% CI, 1.05-1.90) higher colorectal cancer risk. Comparable HRs were 1.44 (95% CI, 1.02-2.01) for colon and 1.34 (95% CI, 0.70-2.56) for rectal cancer.

CONCLUSIONS

Low vitamin D status may lead to elevated colorectal cancer risk in African American women.

IMPACT

Our findings, taken together with established evidence that vitamin D levels are generally lower in African Americans than other U.S. groups, suggest that low vitamin D status may contribute to the disproportionately high colorectal cancer incidence among African Americans.

FDG-PET/CT in colorectal cancer: potential for vascular-metabolic imaging to provide markers of prognosis

PURPOSE

This study assesses the potential for vascular-metabolic imaging with FluoroDeoxyGlucose (FDG)-Positron Emission Tomography/Computed Tomography (PET/CT) perfusion to provide markers of prognosis specific to the site and stage of colorectal cancer.

METHODS

This prospective observational study comprised of participants with suspected colorectal cancer categorized as either (a) non-metastatic colon cancer (M0colon), (b) non-metastatic rectal cancer (M0rectum), or (c) metastatic colorectal cancer (M+). Combined FDG-PET/CT perfusion imaging was successfully performed in 286 participants (184 males, 102 females, age: 69.60 ± 10 years) deriving vascular and metabolic imaging parameters. Vascular and metabolic imaging parameters alone and in combination were investigated with respect to overall survival.

RESULTS

A vascular-metabolic signature that was significantly associated with poorer survival was identified for each patient group: M0colon - high Total Lesion Glycolysis (TLG) with increased Permeability Surface Area Product/Blood Flow (PS/BF), Hazard Ratio (HR) 3.472 (95% CI: 1.441-8.333), p = 0.006; M0rectum - high Metabolic Tumour Volume (MTV) with increased PS/BF, HR 4.567 (95% CI: 1.901-10.970), p = 0.001; M+ participants, high MTV with longer Time To Peak (TTP) enhancement, HR 2.421 (95% CI: 1.162-5.045), p = 0.018. In participants with stage 2 colon cancer as well as those with stage 3 rectal cancer, the vascular-metabolic signature could stratify the prognosis of these participants.

CONCLUSION

Vascular and metabolic imaging using FDG-PET/CT can be used to synergise prognostic markers. The hazard ratios suggest that the technique may have clinical utility.

Fast mutual exclusivity algorithm nominates potential synthetic lethal gene pairs through brute force matrix product computations

Mutual Exclusivity analysis of genomic aberrations contributes to the exploration of potential synthetic lethal (SL) relationships thus guiding the nomination of specific cancer cells vulnerabilities. When multiple classes of genomic aberrations and large cohorts of patients are interrogated, exhaustive genome-wide analyses are not computationally feasible with commonly used approaches. Here we present Fast Mutual Exclusivity (FaME), an algorithm based on matrix multiplication that employs a logarithm-based implementation of the Fisher's exact test to achieve fast computation of genome-wide mutual exclusivity tests; we show that brute force testing for mutual exclusivity of hundreds of millions of aberrations combinations can be performed in few minutes. We applied FaME to allele-specific data from whole exome experiments of 27 TCGA studies cohorts, detecting both mutual exclusivity of point mutations, as well as allele-specific copy number signals that span sets of contiguous cytobands. We next focused on a case study involving the loss of tumor suppressors and druggable genes while exploiting an integrated analysis of both public cell lines loss of function screens data and patients' transcriptomic profiles. FaME algorithm implementation as well as allele-specific analysis output are publicly available at https://github.com/demichelislab/FaME.

The dysregulated expression and functional effect of CaMK2 in cancer

CaMK2 (calcium/calmodulin-dependent protein kinase 2), a multifunctional serine/threonine-protein kinase involved in diverse cellular processes, is vital for the transduction of the Ca²⁺ signaling cascade. Recently, research has highlighted the involvement of CaMK2 in cancer development. However, the specific effects of CaMK2 on cancer have not been fully elucidated. In this review, we summarize not only the altered expression of CaMK2 in a range of cancers, as evidenced by bioinformatics analysis, but also the significant role of CaMK2 in regulating cancer progression, such as proliferation and metastasis. In addition, we described the functional influence of CaMK2 on cancer stemness and resistance. Understanding the critical effects and mechanisms of CaMK2 in cancer would facilitate the development of a promising therapeutic strategy for cancer treatment.

Distinguishing Rectal Cancer from Colon Cancer Based on the Support Vector Machine Method and RNA-sequencing Data

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Several studies have indicated that rectal cancer is significantly different from colon cancer in terms of treatment, prognosis, and metastasis. Recently, the differential mRNA expression of colon cancer and rectal cancer has received a great deal of attention. The current study aimed to identify significant differences between colon cancer and rectal cancer based on RNA sequencing (RNA-seq) data via support vector machines (SVM). Here, 393 CRC samples from the The Cancer Genome Atlas (TCGA) database were investigated, including 298 patients with colon cancer and 95 with rectal cancer. Following the random forest (RF) analysis of the mRNA expression data, 96 genes such as HOXB13, PRAC, and BCLAF1 were identified and utilized to build the SVM classification model with the Leave-One-Out Cross-validation (LOOCV) algorithm. In the training (n=196) and the validation cohorts (n=197), the accuracy (82.1 % and 82.2 %, respectively) and the AUC (0.87 and 0.91, respectively) indicated that the established optimal SVM classification model distinguished colon cancer from rectal cancer reasonably. However, additional experiments are required to validate the predicted gene expression levels and functions.

Low levels of BRCA1 protein expression predict a worse prognosis in stage I-II colon cancer

BACKGROUND

BRCA1 and BRCA2 have been well studied for their roles in tumorigeneis, plus cancer diagnosis and treatment, but their prognostic value in colon cancer, especially for early-stage cancer, has not been fully illuminated. This study examined the expression levels of BRCA1 and BRCA2 proteins in sporadic colon cancer cases and investigated their value in prognosis.

METHODS

The expression levels of BRCA1 and BRCA2 in 275 colon cancer patients who underwent radical surgeries were assayed by immunohistochemical staining in dissected tumor samples. Also, its correlation with clinicopathological characteristics, disease-free survival, and overall survival was investigated.

RESULTS

Tumors with low expression levels of BRCA1, BRCA2, and both were 19.6%, 17.8%, and 6.5%, respectively. The levels of BRCA1/2 expression were not associated with clinicopathological parameters (gender, age, histological differentiation, and tumor node metastasis stage). Patients with low-levels of BRCA1 protein in their tumors demonstrated a lower chance of 5-year disease-free survival (55.6% vs. 69.7%, P=0.046), which was more obvious in the patients with stage I-II tumors without chemotherapy (52.6% vs. 82.6%, P=0.006). Neither BRCA1 nor BRCA2 affected overall survival in this cohort. Multivariate analysis revealed that pathologic stage and the level of BRCA1 protein were independent factors of long-term disease-free survival.

CONCLUSION

This study highlights BRCA1 as an independent prognosticator of early-stage colon cancer.

Differential Expression of miR-20a and miR-145 in Colorectal Tumors as Potential Location-specific miRNAs

BACKGROUND

MicroRNAs (miRNAs), as tissue specific regulators of gene transcription, may be served as biomarkers for Colorectal Cancer (CRC).

OBJECTIVE

This study aimed to investigate the potential role of the cancer-related hsa-miRNAs as biomarkers in Colon Cancer (CC) and Rectal Cancer (RC).

METHODS

A total of 148 CRC samples (74 rectum and 74 colon) and 74 adjacent normal tissues were collected to examine the differential expression of selected ten hsa-miRNAs using quantitative Reverse Transcriptase PCR (qRT-PCR).

RESULTS

The significantly elevated levels of miR-21, miR-133b, miR-18a, miR-20a, and miR-135b, and decreased levels of miR-34a, miR-200c, miR-145, and let-7g were detected in colorectal tumors compared to the healthy tissues (P<0.05). Hsa-miR-20a was significantly overexpressed in rectum compared to colon (p =0.028) from a cut-off value of 3.15 with a sensitivity of 66% and a specificity of 60% and an AUC value of 0.962. Also, hsa-miR-145 was significantly overexpressed in colon compared to the rectum (p =0.02) from a cut-off value of 3.9 with a sensitivity of 55% and a specificity of 61% and an AUC value of 0.91.

CONCLUSION

In conclusion, hsa-miR-20a and hsa-miR-145, as potential tissue-specific biomarkers for distinguishing RC and CC, improve realizing the molecular differences between these local tumors.

Identifications of Candidate Genes Significantly Associated With Rectal Cancer by Integrated Bioinformatics Analysis

INTRODUCTION

Rectal cancer ranks as the eighth in cancer-related morbidity and the tenth in the cancer-related mortality. A few studies have explored several biomarkers for colorectal cancer. However, there is still a great need for us to excavate novel biomarkers with effective and efficient diagnostic and prognostic values to discover the etiology and pathogenesis of rectal cancer separately. Therefore, we aimed to identify more novel candidate genes that were significantly associated with rectal cancer through integrated bioinformatics analysis.

METHODS

We analyzed the gene expression profiles of GSE15781 and GSE20842 from Gene Expression Omnibus database to identify differentially expressed genes between normal rectal tissue and rectal cancer tissue.

RESULTS

We searched for core genes, carried out survival analysis and analyzed the expressions of core genes. We found that 142 genes were significantly upregulated, and 229 genes were significantly downregulated in all 3 independent studies. In KEGG analysis, the upregulated genes were significantly enriched in cytokine-cytokine receptor interaction, IL-17 signaling pathway, cell cycle, etc. The downregulated genes were primarily enriched in nitrogen metabolism, mineral absorption and pentose and glucuronate interconversions. Inhibin subunit beta B (INHBB) expressed markedly higher in rectal cancer tissues compared with normal tissues, and claudins (CLDN) 23 expressed significantly lower in rectal cancer tissues.

CONCLUSION

In conclusion, we discovered that INHBB could provide a great significant diagnostic and prognostic values for rectal cancer.

GAPDH and PUM1: Optimal Housekeeping Genes for Quantitative Polymerase Chain Reaction-Based Analysis of Cancer Stem Cells and Epithelial-Mesenchymal Transition Gene Expression in Rectal Tumors

Background

The overwhelming majority of published articles have taken colon and rectal cancer as a single group, i.e., colorectal cancer, when normalizing gene expression data with housekeeping genes (HKG) in quantitative polymerase chain reaction (qPCR) experiments though there are published reports that suggest the differential expression pattern of genes between the colon and rectal cancer groups and hence the current experiment was attempted to find out the optimal set of housekeeping genes from the list of common HKG for rectal tumor gene expression analysis.

Methods

The expression of five potential housekeeping genes GAPDH, RPNI, PUM1, B2M, and PMM1 was analyzed through qPCR and Bestkeeper software (http://www.wzw.tum.de/gene-quantification/bestkeeper.html) in 20 stage II-IV rectal cancer samples to check for uniformity in their expression pattern. Cancer stem cell (CSC) marker ALDH1 and epithelial-mesenchymal transition marker (EMT) markers E cadherin, vimentin, Twist, and SNAI2 expression were evaluated in conjunction with the two optimal reference genes in 10 rectal cancers as part of validation.

Results

The standard deviation of the cycle threshold value of GAPDH was found the lowest at 0.65 followed by RPN1 at 0.88, PUM1 at 0.94, PMM1 at 0.94, and B2M at 1.21 when analyzed with BestKeeper software. Using GAPDH and PUM1 as the reference gene for the validation phase, rectal cancer patients with stage III/IV showed a 4.79-fold change (P=0.006) in ALDH1 expression, and an 11.76-fold change in Twist expression (P=0.003) with respect to stage II rectal tumor when normalized with GAPDH and PUM1.

Conclusion

GAPDH and PUM1 can be used as an optimal set of housekeeping genes for gene expression-related experiments in rectal tumors. ALDH1 and Twist were found significantly overexpressed in stage III/IV rectal tumors in comparison to stage II rectal cancer. Genes associated with cancer stem cells and EMT markers could be optimally analyzed by normalizing them with GAPDH and PUM1 as housekeeping genes.

Dysregulated PDGFR alpha expression and novel somatic mutations in colorectal cancer: association to RAS wild type status and tumor size

Background

Platelet derived growth factor receptor alpha (PDGFRα) has been considered as a relevant factor in tumor proliferation, angiogenesis and metastatic dissemination. It was a target of tyrosine kinase (TK) inhibitors emerged in the therapy of diverse cancers. In colorectal cancer, the commonly used therapy is anti-epithelial growth factor receptor (EGFR). However, both RAS mutated and a subgroup of RAS wild type patients resist to such therapy. The aim of this study is to investigate PDGFRα protein expression and mutational status in colorectal adenocarcinoma and their association with clinicopathological features and molecular RAS status to provide useful information for the identification of an effective biomarker that might be implicated in prognosis and treatment prediction.

Methods

Our study enrolled 103 formalin fixed paraffin-embedded (FFPE) colorectal adenocarcinoma. PDGFRα expression was investigated by immunohistochemistry (IHC). Hotspot exon 18 of PDGFRA was studied by PCR followed by Sanger sequencing and RAS status was determined by real time quantitative PCR. Thirteen normal colon tissues were used as negative controls.

Results

PDGFRα staining was detected in the cytoplasm of all tissues. Low expression was observed in all normal colon mucosa. In adenocarcinoma, 45% (45/100) of cases showed PDGFRα overexpression. This overexpression was significantly associated with mutations in exon 18 (P = 0.024), RAS wild type status (P < 10^–3), tumor diameter (P = 0.048), whereas there was no association with tumor side (P = 0.13) and other clinicopathological features.

Conclusion

Overexpression of PDGFRα in adenocarcinoma suggests its potential role in tumor cells growth and invasion. The association between PDGFRα overexpression in both tumor and stromal adenocarcinoma cells with RAS wild type status suggests its potential role in anti-EGFR therapy resistance and the relevance of using it as specific or adjuvant therapeutic target.

CAMKIIγ is a targetable driver of multiple myeloma through CaMKIIγ/ Stat3 axis

Aberrant activation of CAMKIIγ has been linked to leukemia and T-cell lymphoma, but not multiple myeloma (MM). The purpose of this study was to explore the role of CaMKIIγ in the pathogenesis and therapy of MM. In this study, we found that CaMKIIγ was aberrantly activated in human MM and its expression level was positively correlated with malignant progression and poor prognosis. Ectopic expression of CaMKIIγ promoted cell growth, colony formation, cell cycle progress and inhibited apoptosis of MM cell lines, whereas, knockdown of CAMKIIγ expression suppressed MM cell growth in vitro and in vivo. Mechanically, we observed that CaMKIIγ overexpression upregulated p-ERK and p-Stat3 levels and suppression of CaMKIIγ had opposite effects. CaMKIIγ is frequently dysregulated in MM and plays a critical role in maintaining MM cell growth through upregulating STAT3 signaling pathway. Furthermore, our preclinical studies suggest that CaMKIIγ is a potential therapeutic target in MM, and could be intervened pharmacologically by small-molecule berbamine analogues.

Identification and functional activity of matrix-remodeling associated 5 (MXRA5) in benign hyperplastic prostate

Objective: Benign prostatic hyperplasia (BPH) is a common condition in aging males. The current study aims to identify differentially expressed genes (DEGs) associated with BPH and to elucidate the role of matrix-remodeling associated 5 (MXRA5) protein and mitogen-activated protein kinase (MAPK) signaling pathways in BPH.

Results: A total of 198 DEGs and a number of related pathways were identified with MXRA5 being one of the most significantly altered DEGs. MXRA5 was upregulated in BPH samples and localized mostly in stroma. Knockdown of MXRA5 induced stromal cell cycle arrest instead of inhibiting apoptosis. Consistently, MXRA5 overexpression enhanced epithelial cell proliferation. In addition, phosphorylated ERK1/2 and p38, key members of the MAPK family, were strongly decreased with knockdown but increased with overexpression.

Conclusion: Our novel data demonstrates that upregulation of MXRA5 in the enlarged prostate could contribute to the development of BPH through increasing cell proliferation via the MAPK pathway. Thus, the MXRA5-MAPK system could be rediscovered as a new therapeutic target for treating BPH.

Methods: Microarray analysis and integrated bioinformatics were conducted. The expression and biologic functions of MXRA5 was investigated via RT-PCR, western-blot, immunofluorescence, flow cytometry and MTT assay. Finally, genes involved in regulation of the MAPK pathway were investigated.

Co-expression Network Analysis Elucidated a Core Module in Association With Prognosis of Non-functioning Non-invasive Human Pituitary Adenoma

Non-functioning pituitary adenomas (NFPAs) are tumors with clinically challenging features since they have insidious progression. A complex network of gene interactions is thought to have roles in tumor formation and progression. Therefore, revealing the genetic network behind NFPA tumorigenesis is not only essential to attain further knowledge of tumor biology, but also plays a fundamental role in the development of efficacious treatment strategies. Differential co-expression network analysis is an outstanding approach for elucidation of groups of genes which show distinct co-expression patterns among phenotypes. In this study, we carried out a differential co-expression network analysis of NFPA-associated transcriptome dataset (n = 40) considering invasive (n = 22) and non-invasive (n = 18) phenotypes. Furthermore, we identified differentially co-expressed and co-regulated mRNA modules, which might be considered as potential systems biomarkers for NFPA prognosis and invasiveness. As a result, we have identified a novel 13-gene module, including CEACAM6, CYP4B1, EIF2S2, HID1, IFFO1, MYO18A, PDCD2, SGIP1, SWSAP1, and four unknown genes (A_24_P127621, A_24_P255786, A_24_P683553, and A_24_P916979), which was able to categorize the patients into two groups as invasive and non-invasive NFPA with distinct prognosis. The prognostic core module genes were associated with progression and prognosis of brain and glandular based cancers as well. Furthermore, these module genes were also expressed in blood, salivary gland, and spinal cord tissues. These results may provide the evidence on featured gene module which might play a prominent role in NFPA prognosis and sub-typing as effective biomarkers and therapeutic targets in the future.

A Propensity Score-adjusted Analysis of the Effects of Ubiquitin E3 Ligase Copy Number Variation in Peripheral Blood Leukocytes on Colorectal Cancer Risk

Background: The ubiquitin ligases E3 (E3s) plays a key role in the specific protein degradation in many carcinogenic biological processes. Colorectal cancer (CRC) development may be affected by the copy number variation (CNV) of E3s. Prior studies may have underestimated the impact of potential confounding factors' effects on the association between gene CNV and CRC risk, and CRC risk predictive model integrating gene CNV patterns is lacking. Our research sought to assess the genes CNVs of MDM2, SKP2, FBXW7, β-TRCP, and NEDD4-1 and CRC risk by using propensity score (PS) adjustment and developing models that integrate CNV patterns for CRC risk predictions.

Methods: This study comprising 1036 participants used traditional regression and different PS techniques to adjust the confounding factors to evaluate the relationships between five gene CNVs and CRC risk, and to establish a CRC risk predictive model. The AUC was applied to evaluate the effect of the model. The categorical net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) were analyzed to evaluate the discriminatory accuracy improvement among the models.

Results: Compared to variable adjustment, the odds ratios (ORs) tended to be conservative and accurate with narrow confidence intervals (CIs) after PS adjustment. After PS adjustment, MDM2 amplification was related to increased CRC risk (Amp-pattern: OR = 8.684, 95% CI: 1.213-62.155, P = 0.031), whereas SKP2 deletion and the (del+amp) genotype were associated with reduced CRC risk (Del-pattern: OR = 0.323, 95% CI: 0.106-0.979, P = 0.046; Var-pattern: OR = 0.339, 95% CI: 0.135-0.854, P = 0.024). The predictive model integrating the gene CNV pattern could correctly reclassify 1.7% of the subjects.

Conclusions: MDM2 amplification and SKP2 CNVs are associated with increased and decreased CRC risk, respectively; abnormal CNV-integrated model is more precise for predicting CRC risk. Further studies are needed to verify these encouraging outcomes.

Regulation of global gene expression in brain by TMP21

TMP21, a type I transmembrane protein of thep24 protein family, mediates protein trafficking and maturation. Dysregulation of TMP21 is implicated in the pathogenesis of Alzheimer’s disease (AD). However, underlying mechanisms remain elusive. To reveal the function of TMP21 in the brain and the pathogenic role of TMP21 in the brain of AD, the global gene expression was profiled in the brain of TMP21 knockdown mice. We found that 8196 and 8195 genes are significantly altered in the hippocampus and cortex, respectively. The genes are involved in a number of brain function-related pathways, including glutamatergic synapse pathway, serotonergic synapse pathway, synaptic vesicle pathway, and long-term depression pathway. Moreover, the network analysis suggests that the TMP21 may contribute to the pathogenesis of AD by regulatingPI3K/Akt/GSK3β signalling pathway. Our study provides an insight into the physiological function of TMP21 in the brain and pathological role of TMP21 in AD.

Identification of protein clusters predictive of tumor response in rectal cancer patients receiving neoadjuvant chemo-radiotherapy

Preoperative neoadjuvant chemoradiotherapy (nCRT) is the gold standard in locally advanced rectal cancer, only 10–30% of patients achieving benefits. Currently, there is a need of a reliable selection of markers for the identification of poor or non-responders prior to therapy. In this work, we compared protein profiles before therapy of patients differing in their responses to nCRT to find novel predictive markers of response to therapy. Patients were grouped into 3 groups according to their tumor regression grading (TRG) after surgery: 'TRG 1–2′, good responders, 'TRG 3′ and 'TRG 4′, poor responders. Paired surgical specimens of rectal cancer and healthy (histologically confirmed) rectal tissues from 15 patients were analysed before nCRT by two dimensional difference in gel electrophoresis followed by mass spectrometry. Thirty spots were found as differentially expressed (p < 0.05). Among them, 3 spots (spots 471, 683 and 684) showed an increased amount of protein in poor responders compared with good responders, and they were more tumor associated compared with healthy tissues. Proteins of these spots were identified as fibrinogen ß chain fragment D, actin isoforms, B9 and B5 serpins, cathepsin D isoforms and peroxiredoxin-4. In an independent validation set of 20 rectal carcinomas we validated the increased fibrinogen ß chain abundance before nCRT in poor responders by immunoblotting. In conclusion, we propose a risk-stratification tool in predicting the response to nCRT treatment in rectal cancer based on the quantity of these proteins.

Identification of the potential biomarkers for the metastasis of rectal adenocarcinoma

Rectal cancer is a common malignant tumor of the digestive tract, with a high incidence and high mortality. This study aimed to identify the potential biomarkers and therapeutic targets for rectal adenocarcinoma (RAC) metastasis. The expression profiling of RAC patients with metastasis and RAC patients without metastasis was downloaded from The Cancer Genome Atlas (TCGA) database. The datasets were used to identify the genes associated with RAC metastasis. Fifty up-regulated genes and seventeen down-regulated genes were identified in the primary tumor loci of RAC metastasis compared with non-metastasis. Sixty-seven dysregulated gens were conducted to construct the protein-protein network, and CCND3 was the hub protein. The dysregulated genes were significantly enriched in pancreatic secretion, cell adhesion molecules pathways, response to vitamin D of biological process, and retinoid binding of molecular function. Quantitative real-time polymerase chain reaction results demonstrated that CCND3, AQP3, PEG10, and RAB27B had the up-regulated tendency in RAC metastasis; ADCY1 had the down-regulated tendency in RAC metastasis. CCND3, AQP3, PEG10, RAB27B, and ADCY1 might play essential roles in the metastasis process of RAC through pancreatic secretion and cell adhesion molecules pathways. The five genes could be potential diagnosis biomarkers or therapeutic targets for RAC metastasis.

Tumor LINE-1 Methylation Level in Association with Survival of Patients with Stage II Colon Cancer

Genome-wide DNA hypomethylation is associated with a worse prognosis in early-stage colorectal cancer. To measure genome-wide DNA methylation levels, long interspersed nucleotide element (LINE-1) repeats are used as a surrogate marker. Cohort studies on the clinical impact of genome-wide DNA methylation level in patients with only early-stage colon cancer, are currently lacking. This study aimed to investigate the prognostic value of LINE-1 methylation in a stage II colon cancer cohort (n = 164). Manual needle microdissection of tumor areas was performed on formalin-fixed paraffin-embedded tumor tissue sections followed by DNA extraction. Bisulfite converted DNA was used to assess tumor LINE-1 methylation level by qPCR. Patients with LINE-1 hypomethylated tumors had a significantly worse overall survival compared to patients with a higher level of LINE-1 tumor DNA methylation (HR 1.68, 95% CI 1.03–2.75; p = 0.04). This effect was more prominent in patients aged over 65 years (HR 2.00, 95% CI 1.13–3.52; p = 0.02), although the test for age interaction was not significant. No significant effect on recurrence-free survival was observed. Based on these results, tumor LINE-1 hypomethylation is associated with a worse overall survival in stage II colon cancer. Whether the origin of this causation is cancer-specific or age-related can be debated.

Emergency presenting colon cancer is an independent predictor of adverse disease-free survival

Twenty percent of colon cancers present as an emergency. However, the association between emergency presentation and disease-free survival (DFS) remains uncertain. Consecutive patients who underwent elective (CC) and emergent (eCC) resection for colon cancer were included in the analysis. Survival outcomes were compared between the 2 groups in univariate/multivariate analyses. A total of 439 patients underwent colonic resection for colon cancer during the interval 2000-2010; 97 (22.1%) presented as an emergency. eCC tumors were more often located at the splenic flexure (P = 0.017) and descending colon (P = 0.004). The eCC group displayed features of more advanced disease with a higher proportion of T4 (P = 0.009), N2 tumors (P < 0.01) and lymphovascular invasion (P< 0.01). eCC was associated with adverse locoregional recurrence (P = 0.02) and adverse DFS (P < 0.01 ) on univariate analysis. eCC remained an independent predictor of adverse locoregional recurrence (HR 1.86, 95% CI 1.50-3.30, P = 0.03) and DFS (HR 1.30, 95% CI 0.88-1.92, P = 0.05) on multivariate analysis. eCC was not associated with adverse overall survival and systemic recurrence. eCC is an independent predictor of adverse locoregional recurrence and DFS.

Correlation of clinical features and genetic profiles of stromal interaction molecule 1 (STIM1) in colorectal cancers

STIM1 overexpression has been observed in a portion of colorectal cancer (CRC) patients and associated with cancer cell invasion and migration. To characterize the distinctive expression profiles associated with stromal interaction molecule 1 (STIM1) overexpression/low-expression between CRC subtypes, and further assess the divergence transcription regulation impact of STIM1 between colon (COADs) and rectum (READs) adenocarcinomas in order to depict the role of SOCE pathway in CRCs, we have conducted a comprehensive phenome-transcriptome-interactome analysis to clarify underlying molecular differences of COADs/READs contributed by STIM1. Results demonstrated that a number of novel STIM1-associated signatures have been identified in COADs but not READs. Specifically, the presence of STIM1 overexpression in COADs, which represented a disturbance of the SOCE pathway, was associated with cell migration and cell motility properties. We identified 11 prognostic mRNA/miRNA predictors associated with the overall survival of COAD patients, suggesting the correlation of STIM1-associated features to clinicopathological outcomes. These findings enhance our understanding on differences between CRC subtypes in panoramic view, and suggested STIM1 as a promising therapeutic biomarker in COADs.

Lysyl Oxidase Gene G473A Polymorphism and Cigarette Smoking in Association with a High Risk of Lung and Colorectal Cancers in a North Chinese Population

The relationship among the lysyl oxidase (LOX) G473A single nucleotide polymorphism (SNP), cigarette smoking and lung, colorectal, colon and rectum cancer susceptibility was studied in 200 cases of lung cancer, 335 cases of colorectal cancer including 130 cases of colon cancer and 205 cases of rectum cancer, and 335 healthy people in Tangshan, China. Peripheral blood DNA samples were collected, DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) performed, followed by multivariate logistic regression analysis. In comparison to LOX473GG genotype carriers, individuals with LOX473AA exhibited a higher susceptibility to lung, colon-rectum, colon, and rectum cancers with OR values amounting to 3.84-, 2.74-, 2.75-, and 2.74-fold of the control, respectively. In the LOX 473AA-positive population, females were more susceptible than males to carcinogenesis with OR values (female vs. male): 5.25 vs. 3.23, 2.29 vs. 1.51, 2.27 vs. 1.45, and 2.25 vs. 1.53, respectively, for lung, colon-rectum combined, colon, and rectum cancers. LOX G473A polymorphism apparently elevated human sensitivity to cigarette smoking carcinogens for eliciting cancers in the lung and colon only. Thus, LOX G473A polymorphism positively correlates with carcinogenesis and it may be used as an ideal intrinsic biomarker for prediction or diagnosis of carcinogenesis in humans.

The emerging role of CaMKII in cancer

Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a multifunctional serine/threonine kinases best known for its critical role in learning and memory. Recent studies suggested that high levels of CaMKII also expressed in variety of malignant diseases. In this review, we focus on the structure and biology properties of CaMKII, including the role of CaMKII in the regulation of cancer progression and therapy response. We also describe the role of CaMKII in the diagnosis of different kinds of cancer and recent progress in the development of CaMKII inhibitors. These data establishes CaMKII as a novel target whose modulation presents new opportunities for cancer diagnosis and treatment.

Elevated CA19-9 as the Most Significant Prognostic Factor in Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiotherapy

It remains controversial regarding the prognostic significance of carbohydrate antigen 19-9 (CA19-9) for locally advanced rectal cancer (LARC) (T3-4/N+) patients with neoadjuvant chemoradiotherapy (neo-CRT). And it is unknown whether CA19-9 can identify patients who may benefit from adjuvant chemotherapy.Overall, 303 LARC patients with neo-CRT between 2004 and 2010 were recruited. Overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and local recurrence-free survival across pretreatment CA19-9 were estimated by Kaplan-Meier method and Cox regression model.In univariate analysis, elevated CA19-9 (>35 U/mL) was significantly correlated with poor OS (P = 0.003), DFS (P = 0.001), and DMFS (P = 0.039). Adjusting for the known covariates, CA19-9 was significantly associated with OS (HR = 1.86, 95% CI 1.03-3.34, P = 0.039) and DFS (HR = 1.74, 95% CI 1.08-2.80, P = 0.024). In the elevated CA19-9 subgroup, patients with adjuvant chemotherapy got much better OS (P < 0.001) and DFS (P = 0.016) than those without. In consideration of both CA19-9 and carcinoembryonic antigen (CEA), we found that patients with both elevated CA19-9 and CEA (>5 ng/mL) got the worst OS (P = 0.021) and DFS (P = 0.006), and significantly benefited from adjuvant chemotherapy in OS (P < 0.001) and DFS (P = 0.026).Pretreatment CA19-9 level is a significant prognostic indicator in patients with LARC following neo-CRT. The addition of CA19-9 to CEA is valuable to discriminate the appropriate patients for adjuvant chemotherapy.

Lymphovascular invasion: a comprehensive appraisal in colon and rectal adenocarcinoma

BACKGROUND

Colon and rectal adenocarcinomas differ at a multitude of levels. The association between outcome and predictor in 1 group may obscure the relationship between outcome and predictor in the other.

OBJECTIVE

The current study aims to evaluate the prognostic properties of lymphovascular invasion in colon and rectal adenocarcinoma separately.

MATERIALS AND METHODS (DESIGN, SETTING AND PATIENTS)

A comparative retrospective analysis was undertaken to determine the prognostic properties of lymphovascular invasion in colon and rectal adenocarcinomas. Patients were classified as lymphovascular invasion positive and lymphovascular invasion negative in separate colon and rectal cancer cohorts. Within cohorts, a univariate analysis was undertaken to determine the association between lymphovascular invasion positivity and local/systemic recurrence and overall/disease-free survival. Findings were evaluated by using Kaplan-Meier estimates, log-rank analysis, and a Cox proportional hazards multivariate model.

MAIN OUTCOME MEASURE

The primary outcomes measured were overall and disease-free survival.

RESULTS

Five hundred twenty-seven patients were included in the analysis (379 with colon cancer and 148 with rectal cancer). On univariate analysis, lymphovascular invasion positivity was associated with adverse locoregional recurrence in colon (p = 0.002) but not rectal adenocarcinoma (p = 0.13). Conversely, lymphovascular invasion positivity was associated with adverse systemic recurrence in rectal (p = 0.002) but not colon adenocarcinoma (p = 0.35). On multivariate analysis, lymphovascular invasion positivity was an independent predictor of adverse disease-free survival in colon (p = 0.02) and rectal adenocarcinoma (p < 0.001). Regarding overall survival, lymphovascular invasion positivity was a poor prognostic indicator in rectal adenocarcinoma only (p = 0.04).

LIMITATIONS AND CONCLUSIONS

In this retrospective analysis, lymphovascular invasion positivity was associated with different patterns of disease recurrence in colon and rectal cancer. Lymphovascular invasion positivity was associated with adverse overall survival in rectal cancer only.

A clinicopathological analysis of KISS1 and KISS1R expression in colorectal cancer

Kisspeptins, the products of the KISS1 gene have tumor suppressing and antimetastatic properties. We aimed to study KISS1 and KISS1R expression in colorectal cancer. We analyzed KISS1 and KISS1R expression using immunohistochemistry and image analysis in normal and malignant tissue samples from 111 patients with colorectal adenocarcinoma. KISS1 expression was much higher in the normal than in the malignant colonic mucosa. Regarding malignant tissues, KISS1 levels were higher in larger tumors, in stage III and IV cancers, in cancers with lymph node metastasis and in tumors located in the distal part of the large intestine. Patients with greater KISS1 levels had worse prognosis. No KISS1R expression was detected in normal or malignant tissues or in liver metastases. KISS1 expression is reduced during the malignant transformation of the colonic mucosa. However, larger and advanced colorectal cancers express more KISS1, without reaching the former normal levels, and increased KISS1 levels are associated with worse prognosis. Finally, neither the normal nor the malignant colonic epithelial cells produce KISS1R.

Identification of commonly dysregulated genes in colorectal cancer by integrating analysis of RNA-Seq data and qRT-PCR validation

The progression of colorectal cancer (CRC) is a multistep process and metastatic CRC is always incurable; consequently, CRC is the leading cause of cancer-related deaths. There is therefore an urgent need for identifying useful biomarkers with enough sensitivity and specificity to detect this disease at early stages, which will significantly reduce the mortality for this malignancy. In this study, we performed an integrating analysis of different RNA-Seq data sets to find new candidate biomarkers for diagnosis, prognosis and as therapeutic targets for this malignancy, as well as to elucidate the molecular mechanisms of CRC carcinogenesis. We identified 883 differentially expressed genes (DEGs) across the studies between CRC and normal control (NC) tissues by combining five RNA-Seq data sets. Gene function analysis revealed high correlation with carcinogenesis. The top 10 most significantly DEGs were further evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) in both rectal cancer (RC) and colon cancer (CC), and the results matched well with integrating data, suggesting that the method of integrating analysis of different RNA-seq data sets is acceptable. Therefore, integrating analysis of different RNA-seq data sets may be a useful way to overcome the limitation of small sample size in a single RNA-seq study. In addition, our study showed that some genes, such as SIM2, ADAMTS6, FOXD4L4 and DNAH5, may have an important role in the development of CRC, which could be applied for diagnosis, prognosis and as therapy for this malignancy. Our findings would also help to understand the pathology of CRC.

Adjuvant chemotherapy after preoperative (chemo)radiotherapy and surgery for patients with rectal cancer: a systematic review and meta-analysis of individual patient data

BACKGROUND

The role of adjuvant chemotherapy for patients with rectal cancer after preoperative (chemo)radiotherapy and surgery is uncertain. We did a meta-analysis of individual patient data to compare adjuvant chemotherapy with observation for patients with rectal cancer.

METHODS

We searched PubMed, Medline, Embase, Web of Science, the Cochrane Library, CENTRAL, and conference abstracts to identify European randomised, controlled, phase 3 trials comparing observation with adjuvant chemotherapy after preoperative (chemo)radiotherapy and surgery for patients with non-metastatic rectal cancer. The primary endpoint of interest was overall survival.

FINDINGS

We analysed data from four eligible trials, including data from 1196 patients with (y)pTNM stage II or III disease, who had an R0 resection, had a low anterior resection or an abdominoperineal resection, and had a tumour located within 15 cm of the anal verge. We found no significant differences in overall survival between patients who received adjuvant chemotherapy and those who underwent observation (hazard ratio [HR] 0.97, 95% CI 0.81-1.17; p=0.775); there were no significant differences in overall survival in subgroup analyses. Overall, adjuvant chemotherapy did not significantly improve disease-free survival (HR 0.91, 95% CI 0.77-1.07; p=0.230) or distant recurrences (0.94, 0.78-1.14; p=0.523) compared with observation. However, in subgroup analyses, patients with a tumour 10-15 cm from the anal verge had improved disease-free survival (0.59, 0.40-0.85; p=0.005, p(interaction)=0.107) and fewer distant recurrences (0.61, 0.40-0.94; p=0.025, p(interaction)=0.126) when treated with adjuvant chemotherapy compared with patients undergoing observation.

INTERPRETATION

Overall, adjuvant fluorouracil-based chemotherapy did not improve overall survival, disease-free survival, or distant recurrences. However, adjuvant chemotherapy might benefit patients with a tumour 10-15 cm from the anal verge in terms of disease-free survival and distant recurrence. Further studies of preoperative and postoperative treatment for this subgroup of patients are warranted.

FUNDING

None.

Prognostic value of HLA class I, HLA-E, HLA-G and Tregs in rectal cancer: a retrospective cohort study

BACKGROUND

Evasion of immune surveillance and suppression of the immune system are important hallmarks of tumorigenesis. The goal of this study was to establish distinct patterns that reflect a rectal tumors' immune-phenotype and to determine their relation to patient outcome.

METHODS

The study population consisted of 495 Stage I-IV non-preoperatively treated rectal cancer patients of which a tissue micro array (TMA) was available. Sections of this TMA were immunohistochemically stained and quantified for presence of Foxp3+ cells (Tregs) and tumor expression of HLA Class I and non-classical HLA-E and HLA-G. All markers were, separate and combined, analyzed for clinical prognostic value.

RESULTS

Expression of HLA class I (DFS HR 0.637 (0.458-0.886), p = 0.013), Foxp3+ infiltration above median (OS HR 0.637 (0.500-0.813), p < 0.001 and DFS HR 0.624 (0.491-0.793), p < 0.001) and expression of HLA-G (DFS HR 0.753 (0.574-0.989), p = 0.042) were related to a better clinical prognosis. When these markers were combined, patients with 2 or 3 markers associated with poor prognosis (loss of HLA Class I, Foxp3+ below median, and weak HLA-G expression), showed a significantly worse survival (OS and DFS p < 0.001). This immune-phenotype was an independent predictor for DFS (HR 1.56 (1.14-2.14), p = 0.019).

CONCLUSIONS

In conclusion, rectal tumors showing loss of HLA class I expression, Foxp3+ infiltration below median and weak HLA-G expression were related to a worse OS and DFS. Combining these immune markers lead to the creation of tumor immune-phenotypes , which related to patient outcome and were significant independent clinical prognostic markers in rectal cancer.

Overall survival is improved in mucinous adenocarcinoma of the colon

INTRODUCTION

Debate persists regarding the relationship between mucin expression and outcome in colon cancer. This arises due to discrepancy in the definition of mucinous adenocarcinoma and the combination of both colon and rectal cancers in analyses. This study examines the relationship between increased mucin production and outcomes in colon cancer.

METHODS

Cases were classified according to the World Health Organization classification of mucinous adenocarcinoma of the colon. Accordingly, tumors were categorized as either (a) mucinous adenocarcinoma of the colon (greater than 50% of the extracellular matrix occupied by mucin) or (b) non-mucinous adenocarcinoma of the colon. Overall survival and disease-free survival were calculated. A stepwise Cox proportional hazards regression model was employed to determine the risk of death/disease recurrence. Kaplan-Meier estimates of overall survival and disease-free survival were plotted for each group and compared using a log-rank test.

RESULTS

On univariate analysis, mucinous adenocarcinoma was associated with reduced risk of death (P = 0.01). On multivariate analysis, mucinous adenocarcinoma was also associated with reduced risk of death (hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.14-0.79, P = 0.01). Kaplan-Meier estimates confirmed improved rate of survival in the mucinous vs. non-mucinous group (P = 0.01). Mucinous adenocarcinoma did not affect disease-free survival (HR 0.75, 95% CI 0.46-1.21, P = 0.22). A comparison of Kaplan-Meier estimates for systemic recurrence demonstrated significant increases in systemic recurrence in the group with no mucin production (P = 0.04) but not for locoregional recurrence (P = 0.24).

CONCLUSIONS

Histopathological evidence of mucinous adenocarcinoma in colon cancer is associated with improved outcomes.

Downregulation of FOXO3a promotes tumor metastasis and is associated with metastasis-free survival of patients with clear cell renal cell carcinoma

PURPOSE

To explore the mechanisms underlying clear-cell renal cell carcinoma (ccRCC) metastasis using transcriptional profiling and bioinformatics analysis of ccRCC samples, and to elucidate the role of FOXO3a in ccRCC metastasis.

EXPERIMENTAL DESIGN

Gene expression profiling was performed using four primary metastatic and five primary nonmetastatic ccRCC samples. The mRNA and protein levels of FOXO3a in ccRCC samples were investigated by real-time reverse transcription PCR and immunohistochemistry, respectively. The association between metastasis-free survival of patients with ccRCC and FOXO3a mRNA levels was analyzed. Biologic functions of FOXO3a in renal cancer cell lines were investigated. The influence of FOXO3a on tumor metastasis was also studied in vivo orthotopic xenograft tumor model. Finally, the mechanism by which FOXO3a attenuation could increase invasion and migration of tumor cells was explored.

RESULTS

Bioinformatics analysis of the profiling data identified FOXO3a as a key factor in ccRCC metastasis. FOXO3a expression was decreased in primary metastatic ccRCC samples. Patients with low FOXO3a mRNA levels had poor metastasis-free survival (P = 0.003). Knocking down FOXO3a induced tumor cell invasion and migration in the nonmetastatic ccRCC cells. Induced FOXO3a overexpression in SN12-PM6 cells could inhibit tumor metastasis in vivo. Downregulation of FOXO3a increased SNAIL1 expression, thereby activating the epithelial-mesenchymal transition (EMT) of RCC cell lines.

CONCLUSIONS

The loss of FOXO3a induced EMT of tumor cells by upregulating SNAIL1, which promoted tumor cells metastasis in vitro and in vivo. Thus, FOXO3a could be considered as an independent prognostic factor in ccRCC metastasis and could be a marker of occult metastases.

Human atrium transcript analysis of permanent atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with increased risks of stroke and heart failure. However, the exact mechanisms of left atrium remodeling and AF-related biological behaviors are not completely understood.The transcripts of left atrium in permanent atrium fibrillation patients (n = 7) were compared with those of healthy heart donors (n = 4) in sinus rhythm using Agilent 4x44K microarrays. Differently expressed genes were analyzed based on Gene Ontology and KEGG and Biocarta pathway analysis databases.We identified 567 down- and 420 up-regulated genes in atrial fibrillation. The majority of the down-regulated genes participated in metabolic processes, particularly that for fatty acids. The most remarkable up-regulating effects were immune and platelet activation. In addition, atrial remodeling including structural, contractile, electrophysiological, neurohormone, and oxidant stress was also observed, suggesting various pathophysiology changes in fibrillating atrium. Nine AF closely related genes were validated by real-time RT-PCR.Some AF specific genes were determined which may be a complement to the mechanism of left atrium remodeling. Metabolic changes and inflammation could promote or aggravate atrial fibrillation.

Differences in survival between colon and rectal cancer from SEER data

Background

Little is known about colorectal cancer or colon and rectal cancer. Are they the same disease or different diseases?

Objectives

The aim of this epidemiology study was to compare the features of colon and rectal cancer by using recent national cancer surveillance data.

Design and setting

Data included colorectal cancer (1995–2008) from the Surveillance, Epidemiology, and End Results Program (SEER) database. Only adenocarcinoma was included for analysis.

Patients

A total of 372,130 patients with a median follow-up of 32 months were analyzed.

Main outcome measures

Mean survival of patients with the same stage of colon and rectal cancer was evaluated.

Results

Around 35% of patients had stage information. Among them, colon cancer patients had better survival than those with rectal cancer, by a margin of 4 months in stage IIB. In stage IIIC and stage IV, rectal cancer patients had better survival than colon cancer patients, by about 3 months. Stage IIB colorectal cancer patients had a poorer prognosis than those with stage IIIA and IIIB colorectal cancer. After adjustment of age, sex and race, colon cancer patients had better survival than rectal cancer of stage IIB, but in stage IIIC and IV, rectal cancer patients had better survival than colon cancer.

Limitations

The study is limited by its retrospective nature.

Conclusion

This was a population-based study. The prognosis of rectal cancer was not worse than that of colon cancer. Local advanced colorectal cancer had a poorer prognosis than local regional lymph node metastasis. Stage IIB might require more aggressive chemotherapy, and no less than that for stage III.

KISS1 expression in colorectal cancer

Kisspeptins, the products of the KISS1 gene, are involved in cancer invasion, migration, metastasis and angiogenesis, while they induce apoptosis in various cancers. Herein, we studied KISS1 expression in colorectal cancer. We analyzed KISS1 expression using immunohistochemistry and image analysis in normal and malignant tissue samples from 60 patients with colorectal adenocarcinoma. The results correlated with various clinicopathological parameters. The expression of KISS1 was much higher in normal than in malignant colonic mucosa. However, among malignant tissues, KISS1 expression was higher in larger tumors (>4 cm) than in smaller ones (≤4 cm) and in stages III and IV than in stages I and II. In addition, it was higher in patients with lymph node metastases. Moreover, KISS1 levels in the normal mucosa and their difference from those in the malignant mucosa were higher in the right part of the large intestine than in the left one. KISS1 expression is reduced during the malignant transformation of the colonic mucosa and there is a difference in the expression pattern between the right and the left part of the large intestine. However, larger and advanced colorectal tumors express higher KISS1 levels than smaller and localized ones.

Expression of miR-126 and miR-508-5p in endothelial progenitor cells is associated with the prognosis of chronic heart failure patients

BACKGROUND

MicroRNA (miRNA) expression profiles in endothelial progenitor cells (EPCs) contribute to EPC dysfunction in patients suffering from coronary artery disease. However, it remains unclear whether miRNA expression in EPCs is associated with the prognosis of chronic heart failure (CHF) secondary to ischemic cardiomyopathy (ICM) or non-ischemic cardiomyopathy (NICM).

METHODS AND RESULTS

One hundred six patients with CHF (55 ICM and 51 NICM) and 30 healthy controls were followed until the end of 24 months or when the end point was obtained (cardiovascular death). The miRNA expression profile was analyzed by TaqMan Human MicroRNA Array Set v2.0 in 30 randomly assigned samples (ICM=10, NICM=10, and healthy controls=10). During the 24-month follow-up, 26 patients died from cardiovascular disease. Sixteen miRNAs (miR-126, miR-508-5p, miR-34a, miR-210, miR-490-3p, miR-513-5p, miR-517c, miR-518e, miR-589, miR-220c, miR-200a*, miR-186*, miR-7i*, miR-200b*, miR-595, and miR-662) were found to be differentially expressed between ICM and NICM patients. Survival analysis showed that miR-126 and miR-508-5p levels in EPCs were independent prognostic factors (P=0.003; HR (hazard ratio): 0.19; 95% CI (confidence intervals): 0.06-0.58, P=0.002; HR: 2.292; 95% CI: 1.37-3.84) for the outcome of ICM or NICM patients with CHF. Pathway enrichment analysis showed that the angiogenesis pathway was the most likely pathway regulated by miR-126 and miR-508-5p.

CONCLUSIONS

The miRNAs miR-126 and miR-508-5p are associated with the outcome of ICM and NICM patients with CHF. These two miRNAs could be useful in the diagnosis of CHF patients, and might provide novel targets for prevention and treatment of CHF.