Three-dimensional residual channel attention networks denoise and sharpen fluorescence microscopy image volumes.

We demonstrate residual channel attention networks (RCAN) for the restoration and enhancement of volumetric time-lapse (four-dimensional) fluorescence microscopy data. First we modify RCAN to handle image volumes, showing that our network enables denoising competitive with three other state-of-the-art neural networks. We use RCAN to restore noisy four-dimensional super-resolution data, enabling image capture of over tens of thousands of images (thousands of volumes) without apparent photobleaching. Second, using simulations we show that RCAN enables resolution enhancement equivalent to, or better than, other networks. Third, we exploit RCAN for denoising and resolution improvement in confocal microscopy, enabling ~2.5-fold lateral resolution enhancement using stimulated emission depletion microscopy ground truth. Fourth, we develop methods to improve spatial resolution in structured illumination microscopy using expansion microscopy data as ground truth, achieving improvements of ~1.9-fold laterally and ~3.6-fold axially. Finally, we characterize the limits of denoising and resolution enhancement, suggesting practical benchmarks for evaluation and further enhancement of network performance.

Gallic acid attenuates metastatic potential of human colorectal cancer cells through the miR-1247-3p-modulated integrin/FAK axis.

Colorectal cancer (CRC) exhibits highly metastatic potential even in the early stages of tumor progression. Gallic acid (GA), a common phenolic compound in plants, is known to possess potent antioxidant and anticancer activities, thereby inducing cell death or cell cycle arrest. However, whether GA reduces the invasiveness of CRC cells without inducing cell death remains unclear. Herein, we aimed to investigate the antimetastatic activity of low-dose GA on CRC cells and determine its underlying mechanism. Cell viability and tumorigenicity were analyzed by MTS, cell adhesion, and colony formation assay. Invasiveness was demonstrated using migration and invasion assays. Changes in protein phosphorylation and expression were assessed by Western blot. The involvement of microRNAs was validated by microarray analysis and anti-miR antagonist. Our findings showed that lower dose of GA (≤100 µM) did not affect cell viability but reduced the capabilities of colony formation, cell adhesion, and invasiveness in CRC cells. Cellularly, GA downregulated the cellular level of integrin αV/ß3, talin-1, and tensin and diminished the phosphorylated FAK, paxillin, Src, and AKT in DLD-1 cells. Microarray results revealed that GA increased miR-1247-3p expression, and pretreatment of anti-miR antagonist against miR-1247-3p restored the GA-reduced integrin αV/ß3 and the GA-inhibited paxillin activation in DLD-1 cells. Consistently, the in vivo xenograft model showed that GA administration inhibited tumor growth and liver metastasis derived from DLD-1 cells. Collectively, our findings indicated that GA inhibited the metastatic capabilities of CRC cells, which may result from the suppression of integrin/FAK axis mediated by miR1247-3p.

Health-related quality of life and cost comparison of adjuvant capecitabine versus 5-fluorouracil/leucovorin in stage III colorectal cancer patients.

PURPOSE: The purpose of this study was to compare health-related quality of life (HRQoL) and costs associated with 2 adjuvant chemotherapy regimens [capecitabine-based therapy versus 5-fluorouracil/leucovorin (5-FU/LV)-based therapy] in stage III colorectal cancer patients. METHODS: We conducted a prospective, open-label, observational, multicenter study from July 2008 to July 2011. The European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 questionnaires was used to assess HRQoL before, during, and after treatment. The direct and indirect costs of adjuvant treatment were estimated from a specially prepared questionnaire, the National Health Insurance Research Database, and other published sources. We used propensity scoring to match samples between groups and performed multivariate analyses to adjust for differences in patient demographics and clinical characteristics. RESULTS: A total of 497 patients were enrolled, and 356 completed the surveys. Following propensity score matching, 239 patients were included in the analysis (122 in the capecitabine-based group, 117 in the 5-FU/LV-based group). Global HRQoL scores did not differ significantly between the two groups. However, compared to patients in the 5-FU/LV-based group, patients in the capecitabine-based group had less nausea and vomiting (mid-term, P = 0.024; final, P = 0.013), appetite loss (mid-term, P < 0.0001; final, P = 0.001), and fewer side effects from chemotherapy (mid-term, P = 0.017). In addition, the monthly cost of capecitabine-based therapy was lower than those of 5-FU/LV-based therapy [NT$31,895.46 (US$1063.18) vs. NT$79,159.24 (US$2638.64) per patient]. CONCLUSIONS: Capecitabine is a reasonable alternative and cost-effective treatment option under current conditions for patients with stage III colorectal cancer.

MicroRNA-21 promotes tumour malignancy via increased nuclear translocation of ß-catenin and predicts poor outcome in APC-mutated but not in APC-wild-type colorectal cancer.

MiR-21 has been associated with poor prognosis in colon adenocarcinomas. However, in our preliminary data, the prognostic value of miR-21 levels was observed only in adenomatous polyposis coli (APC)-mutated tumours, not in APC-wild-type tumours. We explored whether ß-catenin nuclear translocation was synergistically promoted by miR-21 in APC-mutated cells but not in APC-wild-type cells. We enrolled 165 colorectal tumour to determine APC mutation, miR-21 levels and nuclear ß-catenin expression by direct sequencing, real-time PCR and immunohistochemistry. Overall survival and relapse-free survival were analysed by Kaplan-Meier and Cox regression models. The mechanistic action of ß-catenin nuclear translocation modulated by miR-21 and its effect on cell invasion were evaluated in a cell model. Positive nuclear ß-catenin expression was more commonly occurred in APC-mutated tumours than in APC-wild-type tumours. High miR-21 levels were relatively more common in tumours with positive nuclear ß-catenin expression than in those with negative nuclear ß-catenin expression. APC-mutated tumours with high miR-21 levels had shorter overall survival and relapse-free survival periods compared with others. However, the prognostic value of miR-21 levels was not observed in APC-wild-type tumours. Phosphorylation of ß-catenin at Ser552 via the miR-21-mediated PTEN/AKT axis plays a critical role in ß-catenin nuclear translocation in APC-mutated cells but not in APC-wild-type cells. Moreover, nuclear ß-catenin expression increased by miR-21 is responsible for the capability of invasiveness. In summary, nuclear translocation of ß-catenin increased by miR-21 promotes tumour malignancy and a poor outcome in APC-mutated patients but not in APC-wild-type colorectal cancer.

LKB1 loss at transcriptional level promotes tumor malignancy and poor patient outcomes in colorectal cancer.

BACKGROUND: Liver kinase B1 (LKB1) loss by gene mutation, loss of heterozygosity, and promoter methylation rarely occurs in colorectal cancer. We wondered whether LKB1 loss could be deregulated at the transcriptional level to promote tumor progression and poor outcome in colorectal cancer. METHODS: Mechanistic studies were performed in two each of p53 wild-type (HCT116, LoVo) and p53-mutated (SW480, HT29) colon cancer cells to explore whether LKB1 loss could be deregulated by NKX2-1-mediated p53 pathway. LKB1 and NK2 homeobox 1 (NKX2-1) expressions in colorectal tumors were determined by immunohistochemistry, and the prognostic value of both molecules was assessed by Kaplan-Meier test and Cox regression model. RESULTS: Mechanistically, LKB1 loss at the transcriptional level due to alteration of the NKX2-1-mediated p53 pathway promotes invasiveness in colon cancer cells. The cell invasiveness induced by LKB1 loss was nearly suppressed by mammalian target of rapamycin (mTOR) inhibitor (rapamycin and everolimus) and mTOR/AKT dual inhibitor Palomid 529 (P529). Among patients, low LKB1 tumors exhibited shorter overall survival (OS) and relapse-free survival periods than high LKB1 tumors. The highest hazard ratio value for OS and relapse-free survival was observed in wild-type p53 with low LKB1/low NKX2-1 tumors and in mutated p53 with low LKB1/high NKX2-1 tumors when wild-type p53 with high LKB1/high NKX2-1 and mutated p53 with high LKB1/low NKX2-1 tumors were used as references. CONCLUSIONS: LKB1 loss at the transcriptional level via alteration of the NKX2-1/p53 axis promotes cell invasion, consequently resulting in poor outcome in colorectal cancer patients.

SYF2 suppression mitigates neurodegeneration in models of diverse forms of ALS.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease caused by many diverse genetic etiologies. Although therapeutics that specifically target causal mutations may rescue individual types of ALS, such approaches cannot treat most patients since they have unknown genetic etiology. Thus, there is a critical need for therapeutic strategies that rescue multiple forms of ALS. Here, we combine phenotypic chemical screening on a diverse cohort of ALS patient-derived neurons with bioinformatic analysis of large chemical and genetic perturbational datasets to identify broadly effective genetic targets for ALS. We show that suppressing the gene-encoding, spliceosome-associated factor SYF2 alleviates TDP-43 aggregation and mislocalization, improves TDP-43 activity, and rescues C9ORF72 and causes sporadic ALS neuron survival. Moreover, Syf2 suppression ameliorates neurodegeneration, neuromuscular junction loss, and motor dysfunction in TDP-43 mice. Thus, suppression of spliceosome-associated factors such as SYF2 may be a broadly effective therapeutic approach for ALS.

The Impact of Matrix Metalloproteinase-11 Polymorphisms on Colorectal Cancer Progression and Clinicopathological Characteristics.

Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide and the most prevalent cancer in Taiwan. The matrix metalloproteinase (MMP)-11 is a proteolytic enzyme of the MMP family which is involved in extracellular matrix degradation and tissue remodeling. In this study, we focused on the associations of MMP-11 single-nucleotide polymorphisms (SNPs) with CRC susceptibility and clinicopathological characteristics. The MMP-11 SNPs rs131451, rs738791, rs2267029, rs738792, and rs28382575 in 479 controls and 479 patients with CRC were analyzed with real-time polymerase chain reaction. We found that the MMP-11 SNP rs738792 "TC + CC" genotype was significantly associated with perineural invasion in colon cancer patients after controlling for clinical parameters [OR (95% CI) = 1.783 (1.074-2.960); p = 0.025]. The MMP-11 rs131451 "TC + CC" genotypic variants were correlated with greater tumor T status [OR (95% CI):1.254 (1.025-1.534); p = 0.028] and perineural invasion [OR (95% CI):1.773 (1.027-3.062); p = 0.040) in male CRC patients. Furthermore, analyses of The Cancer Genome Atlas (TCGA) revealed that MMP-11 levels were upregulated in colorectal carcinoma tissue compared with normal tissues and were correlated with advanced stage, larger tumor sizes, and lymph node metastasis. Moreover, the data from the Genotype-Tissue Expression (GTEx) database exhibited that the MMP-11 rs738792 "CC" and "CT" genotypic variants have higher MMP-11 expression than the "TT" genotype. In conclusion, our results have demonstrated that the MMP-11 SNPs rs738792 and rs131451 may have potential to provide biomarkers to evaluate CRC disease progression, and the MMP-11 rs131451 polymorphism may shed light on sex discrepancy in CRC development and prognosis.

Impact of carbonic anhydrase 9 gene polymorphism on the progression of colorectal cancer.

Colorectal cancer (CRC) is a commonly occurring tumor type worldwide, and its development is governed by a connection between genetic variations and acquired factors. Carbonic anhydrase 9 (CA9) is a cell-surface pH modulator that has been demonstrated to contribute to key steps of cancer progression. Here, we attempted to interrogate the effect of CA9 gene polymorphisms on the development of CRC in 470 cases and 470 gender- and age-matched non-cancer controls. We found that none of three CA9 single-nucleotide polymorphisms (SNPs) tested, including rs2071676, rs3829078, and rs1048638, was significantly associated with the occurrence of CRC. Yet, while evaluating the clinicopathological variables, cases carrying at least one reference allele (G allele) of rs2071676 tended to develop poorly differentiated tumors less frequently than those who are homozygous for the alternative allele (A allele) of rs2071676 (GA+GG vs AA; OR, 0.483; 95% CI, 0.242-0.963; p=0.036). Further stratification revealed that as compared to homozygous carriers of the alternative allele (AA), cases of colon cancer bearing at least one reference allele of rs2071676 (GA+GG) less frequently developed poorly differentiated tumors (OR, 0.449; 95% CI, 0.221-0.911; p=0.024) and lymphovascular invasion (OR, 0.570; 95% CI, 0.361-0.900; p=0.015). Such genetic effect was exclusively observed in colon cancer but not in rectal cancer. Our results indicate an anatomical site-specific impact of CA9 gene polymorphisms on modulating the progression of colorectal malignancies.

Co-inhibition of Aurora A and Haspin kinases enhances survivin blockage and p53 induction for mitotic catastrophe and apoptosis in human colorectal cancer.

Colorectal cancer (CRC) is a leading cause and mortality worldwide. Aurora A and haspin kinases act pivotal roles in mitotic progression. However, the blockage of Aurora A and Haspin for CRC therapy is still unclear. Here we show that the Haspin and p-H3T3 protein levels were highly expressed in CRC tumor tissues of clinical patients. Overexpression of Haspin increased the protein levels of p-H3T3 and survivin in human CRC cells; conversely, the protein levels of p-H3T3 and survivin were decreased by the Haspin gene knockdown. Moreover, the gene knockdown of Aurora A induced abnormal chromosome segregation, mitotic catastrophe, and cell growth inhibition. Combined targeted by co-treatment of CHR6494, a Haspin inhibitor, and MLN8237, an Aurora A inhibitor, enhanced apoptosis and CRC tumor inhibition. MLN8237 and CHR6494 induced abnormal chromosome segregation and mitotic catastrophe. Meanwhile, MLN8237 and CHR6494 inhibited survivin protein levels but conversely induced p53 protein expression. Ectopic survivin expression by transfection with a survivin-expressed vector resisted the cell death in the MLN8237- and CHR6494-treated cells. In contrast, the existence of functional p53 increased the apoptotic levels by treatment with MLN8237 and CHR6494. Co-treatment of CHR6494 and MLN8237 enhanced the blockage of human CRC xenograft tumors in nude mice. Taken together, co-inhibition of Aurora A and Haspin enhances survivin inhibition, p53 pathway induction, mitotic catastrophe, apoptosis and tumor inhibition that may provide a potential strategy for CRC therapy.

Relative down-regulation of apoptosis and autophagy genes in colorectal cancer.

BACKGROUND: Cancer is often caused by disturbance in the regulation and/or execution of programmed cell death (PCD, including apoptosis and autophagy). Our aim was to investigate these two pathways simultaneously in the same samples to understand further the pathological roles of PCDs in colorectal cancer. MATERIALS AND METHODS: Real time quantitative PCR (RT-qPCR) array was used to analyse the mRNA levels of 22 apoptosis and autophagy-related genes involved in pro- and anti-action of the pathways in 15 paired (tumour and non-cancerous part) colorectal samples using Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as the reference gene. RESULTS: GAPDH mRNA content was significantly higher (approximately 4·01 fold) in tumour tissue than that of paired non-cancerous part. The absolute mRNA levels for most of the 22 genes were higher in the tumour tissue also. However, after normalization with GAPDH Ct, the expressions of all the analysed genes were decreased in the tumour tissues, except for damage-regulated autophagy modulator (DRAM). The expression of most of the genes involved in the same pathway was closely correlated to each other in both tumour and non-cancerous tissues, and the correlation of tumour necrosis factor receptor (TNFR) and Akt to other genes in the same pathway was increased in tumour tissues. CONCLUSIONS: The high level expression of GAPDH might reflect the metabolic state of cancer cells, and PCDs were down-regulated in the tumour tissues when metabolic state was taken into consideration. This relative suppression of PCDs in tumour tissue is supposed to be in favour of cancer cell survival.

Interactive association between dietary fat and sex on CDH13 cg02263260 methylation.

BACKGROUND: DNA methylation of Cadherin 13 (CDH13), a tumor suppressor gene is associated with gene repression and carcinogenesis. We determined the relation of dietary fat and sex with CDH13 cg02263260 methylation in Taiwanese adults. METHODS: Data of 870 eligible participants (430 men and 440 women) between 30 and 70 years were obtained from the Taiwan Biobank (TWB) database. The association of dietary fat and sex with CDH13 cg02263260 methylation was determined using multiple linear regression. RESULTS: The association between sex and cg02263260 methylation was significant: beta-coefficient (ß) = 0.00532; 95% confidence interval (CI) = 0.00195-0.00868. Moreover, the interaction between sex and dietary fat on cg02263260 methylation was significant (P-value = 0.0145). After stratification by sex, the association of dietary fat with cg02263260 methylation was significant only in women. Specifically, high dietary fat was positively associated with cg02263260 methylation in women (ß = 0.00597; 95% CI = 0.00061-0.01133) and the test for trend was significant (P-value = 0.0283). CONCLUSION: High fat intake was significantly associated with higher cg02263260 methylation in women and the test for trend was significant. These findings suggest that the association of fat intake and CDH13 cg02263260 might vary by sex and CDH13 cg02263260 methylation levels in women might increase as fat intake increases.

Impact of FGFR4 Gene Polymorphism on the Progression of Colorectal Cancer.

Colorectal cancer (CRC) is a multifactorial malignancy, and its high incidence and mortality rate remain a global public health burden. Fibroblast growth factor receptor 4 (FGFR4) is a receptor tyrosine kinase that has been shown to play a key role in cancer development and prognosis via the activation of its downstream oncogenic signaling pathways. The present study aimed to explore the impact of FGFR4 gene polymorphisms on the risk and progression of CRC. Three FGFR4 single-nucleotide polymorphisms (SNPs), including rs1966265, rs351855, and rs7708357, were evaluated in 413 CRC cases and 413 gender- and age-matched cancer-free controls. We did not observe any significant association of three individual SNPs with the risk of CRC between the case and control group. However, while assessing the clinicopathological parameters, patients of rectal cancer possessing at least one minor allele of rs1966265 (AG and GG; AOR, 0.236; p = 0.046) or rs351855 (GA and AA; AOR, 0.191; p = 0.022) were found to develop less metastasis as compared to those who are homozygous for the major allele. Further analyses using the datasets from the Genotype-Tissue Expression (GTEx) Portal and The Cancer Genome Atlas (TCGA) revealed that rs351855 regulated FGFR4 expression in many human tissues, and increased FGFR4 levels were associated with the occurrence, advanced stage, and distal metastasis of colon adenocarcinoma. These data suggest that the amino acid change in combination with altered expression levels of FGFR4 due to genetic polymorphisms may affect CRC progression.

Elastin in oral connective tissue modulates the keratinization of overlying epithelium.

AIM: One of the most discernable differences between keratinized and non-keratinized oral mucosas is the quantity of elastin they contain in the connective tissues. Whether elastin modulates the keratin expression of oral epithelial cells is unknown. METHODS: Four specimens containing both keratinized and non-keratinized mucosas were processed for immunohistochemical (IHC) stainings for elastin and four keratins. Six keratinized and non-keratinized portions of oral mucosas were dissected and cultured on an organ culture system. Purified elastin and elastase were added separately to the media. After 14 days, the mucosas were examined for four keratin expressions. Cell cultures of keratinized and non-keratinized gingival fibroblasts were established and tested for elastin expression. Oral mucosa equivalents were then engineered and tested for keratin expression. RESULTS: Keratinized epithelium exclusively expressed keratin-1 and -10 (K1/10), while non-keratinized epithelium expressed keratin-4 and -13 (K4/13). Only non-keratinized fibroblasts expressed elastin in cell culture. Both the native and the engineered keratinized gingiva changed phenotypes and expressed K4/13 when treated with exogenous elastin. On the contrary, the native non-keratinized mucosa started to express K1/10 when elastase eradicated inherent elastin. CONCLUSIONS: Our study demonstrated that the elastin in the oral connective tissue is important for the non-keratinized phenotypes of overlaying epithelium.

EP4 upregulation of Ras signaling and feedback regulation of Ras in human colon tissues and cancer cells.

Previous studies indicate that COX-2 and prostaglandin E(2) (PGE(2)) receptor subtypes are involved in intestinal carcinogenesis and activation of downstream pathways. In this report, we try to understand the association of PGE(2) receptor and K-ras cellular mechanism during the development of colorectal cancer. We collected 21 colorectal cancer patients and compared the protein expression of tumor tissues and normal mucosa tissues by using immunoblot. Furthermore, we transferred empty vector and pcDNA-K-ras into Ras-HT29 colon cancer cells. Result showed that phosphorylation of Akt and EP(1)/EP(4) were over-expressed in the colorectal tumor tissue. K-ras induces HT29 cells proliferation through the expressions of COX-2, EP1/EP4, pAkt, GSK3beta and increases Tcf transcriptional factor activation. Additionally, Ras protein was suppressed when treated with EP(4) inhibitor in Ras-HT29 cell. In cell cycle assay, K-ras mutation causing cell cycle S phase was prolonged with an increase in the G2/M phase ratio. In conclusion, we suggested that Ras overexpression leads to cell proliferation through activating Ras/PI3K/GSK3beta/EP(4) PGE(2) receptor signals and caused a feedback regulation of Ras by EP4 in colorectal tumor progression.

Effect of citronellol and the Chinese medical herb complex on cellular immunity of cancer patients receiving chemotherapy/radiotherapy.

Leukopenia and immunity impairment usually occur during cancer therapy. Citronellol, an oil soluble compound derived from the geranium, has anticancer and antiinflammatory properties, as well as promoting wound healing. Ganoderma lucidum, Codonopsis pilosula and Angelicae sinensis are traditional Chinese herbs, all of which have proven immunomodulatory functions in laboratory-based research. This randomized, double-blind, placebo-controlled study examined whether the Chinese medicinal herb complex (CCMH; a mixture of citronellol and extracts of G. lucidum, C. pilosula and A. sinensis) improves the immune cell counts of cancer patients receiving chemotherapy and/or radiotherapy. A total of 105 cancer patients receiving chemotherapy or radiotherapy were enrolled. The quantities of immune cells in the blood of the subjects were determined before and after 6 weeks of cancer treatment, with either CCMH or a placebo. CCMH significantly reduced the depletion of leukocytes (14.2% compared with 28.2%) and neutrophils (11.0% compared with 29.1%). Analysis of the lymphocyte phenotype revealed that the patients receiving the placebo had reduced CD4 lymphocytes and natural killer (NK) cells than the CCMH-treated patients. Treatment with CCMH for patients receiving chemotherapy and/or radiotherapy may improve their immune function, improving their ability to fight off the cancer, as well as any secondary infections that could compromise their treatment and their health.

Dietary delphinidin inhibits human colorectal cancer metastasis associating with upregulation of miR-204-3p and suppression of the integrin/FAK axis.

Delphinidin is a flavonoid belonging to dietary anthocyanidin family that has been reported to possess diverse anti-tumoral activities. However, the effects of delphinidin on colorectal cancer (CRC) cells and the underlying mechanisms are not fully understood. Thus, we aimed to investigate the anti-cancer activity of delphinidin in CRC cells and the underlying molecular mechanisms. The effects of delphinidin on the viability, metastatic characteristics, signaling, and microRNA (miR) profile of human CRC cell lines used were analyzed. In vivo metastasis was also evaluated using xenograft animal models. Our findings showed that delphinidin (<100 µM) inhibited the colony formation of DLD-1, SW480, and SW620 cells, but non-significantly affected cell viability. Delphinidin also suppressed the migratory ability and invasiveness of the tested CRC cell lines, downregulated integrin αV/ß3 expression, inhibited focal adhesion kinase (FAK)/Src/paxillin signaling, and interfered with cytoskeletal construction. Analysis of the miR expression profile revealed a number of miRs, particularly miR-204-3p, that were significantly upregulated and downregulated by delphinidin. Abolishing the expression of one upregulated miR, miR-204-3p, with an antagomir restored delphinidin-mediated inhibition of cell migration and invasiveness in DLD-1 cells as well as the αV/ß3-integrin/FAK/Src axis. Delphinidin also inhibited the lung metastasis of DLD-1 cells in the xenograft animal model. Collectively, these results indicate that the migration and invasion of CRC cells are inhibited by delphinidin, and the mechanism may involve the upregulation of miR-204-3p and consequent suppression of the αV/ß3-integrin/FAK axis. These findings suggest that delphinidin exerts anti-metastatic effects in CRC cells by inhibiting integrin/FAK signaling and indicate that miR-204-3p may play an important role in CRC metastasis.

Enterotype-based Analysis of Gut Microbiota along the Conventional Adenoma-Carcinoma Colorectal Cancer Pathway.

The dysbiosis of human gut microbiota is strongly associated with the development of colorectal cancer (CRC). The dysbiotic features of the transition from advanced polyp to early-stage CRC are largely unknown. We performed a 16S rRNA gene sequencing and enterotype-based gut microbiota analysis study. In addition to Bacteroides- and Prevotella-dominated enterotypes, we identified an Escherichia-dominated enterotype. We found that the dysbiotic features of CRC were dissimilar in overall samples and especially Escherichia-dominated enterotype. Besides a higher abundance of Fusobacterium, Enterococcus, and Aeromonas in all CRC faecal microbiota, we found that the most notable characteristic of CRC faecal microbiota was a decreased abundance of potential beneficial butyrate-producing bacteria. Notably, Oscillospira was depleted in the transition from advanced adenoma to stage 0 CRC, whereas Haemophilus was depleted in the transition from stage 0 to early-stage CRC. We further identified 7 different CAGs by analysing bacterial clusters. The abundance of microbiota in cluster 3 significantly increased in the CRC group, whereas that of cluster 5 decreased. The abundance of both cluster 5 and cluster 7 decreased in the Escherichia-dominated enterotype of the CRC group. We present the first enterotype-based faecal microbiota analysis. The gut microbiota of colorectal neoplasms can be influenced by its enterotype.

PSMD4 is a novel therapeutic target in chemoresistant colorectal cancer activated by cytoplasmic localization of Nrf2.

Nuclear Nrf2 (nNrf2) binding to the antioxidant response element may promote chemoresistance in colorectal cancer. However, the shuttling of Nrf2 between cytoplasm and nucleus in colon cancer cells has revealed the possibility that cytoplasmic location of Nrf2 (cNrf2) may play a specific role in chemoresistance. Transfection of a nuclear location sequence (NLS)-wild-type or NLS-mutated Nrf2 expression vector into a stable shNrf2 HCT116 clone using the MTT assay to examine whether chemoresistance induced by cNrf2 may be greater than nNrf2. Different specific inhibitors and small hairpin (sh)RNAs of targeting genes were used to verify the mechanistic action of cNrf2 in chemoresistance and further confirmed by an animal model. The association of cNrf2 with chemotherapeutic response in patients with colorectal cancer was statistically analyzed. The MTT assay indicated that cNrf2 may play a more important role than nNrf2 in conferring 5-fluorouracil (5-FU) and oxaliplatin resistance in HCT116 cells. Mechanistically, cNrf2-induced PSMD4 expression was responsible for chemoresistance in the NLS-mutated Nrf2-tranfected shNrf2HCT116 clone via the NF-κB/AKT/ß-catenin/ZEB1 cascades. The tumor burden induced by the NLS-mutated Nrf2-transfected shNrf2HCT116 clone was completely suppressed by treatment with 5-FU in combination with carfilzomib. A higher prevalence of unfavorable chemotherapeutic response in colorectal cancer patients with cNrf2, PSMD4-positive, p-p65-positive, and nuclear ß-catenin tumors was observed when compared to their counterparts. cNrf2 may play a more important role than nNrf2 in the chemoresistance of colorectal cancer. Activation of the NF-κB/AKT/ß-catenin/ZEB1 cascade by PSMD4 may be responsible for cNrf2-mediated chemoresistance. CONDENSED ABSTRACT: CNrf2 may play a more important role than nNrf2 in conferring 5-FU and oxaliplatin resistance. This observation in patients seemed to support the findings of the cell and animal models and suggested that PSMD4 may be responsible cNrf2-mediated chemoresistance via the NF-κB/AKT/ß-catenin /ZEB1 cascades.

PClass: Protein Quaternary Structure Classification by Using Bootstrapping Strategy as Model Selection.

Protein quaternary structure complex is also known as a multimer, which plays an important role in a cell. The dimer structure of transcription factors is involved in gene regulation, but the trimer structure of virus-infection-associated glycoproteins is related to the human immunodeficiency virus. The classification of the protein quaternary structure complex for the post-genome era of proteomics research will be of great help. Classification systems among protein quaternary structures have not been widely developed. Therefore, we designed the architecture of a two-layer machine learning technique in this study, and developed the classification system PClass. The protein quaternary structure of the complex is divided into five categories, namely, monomer, dimer, trimer, tetramer, and other subunit classes. In the framework of the bootstrap method with a support vector machine, we propose a new model selection method. Each type of complex is classified based on sequences, entropy, and accessible surface area, thereby generating a plurality of feature modules. Subsequently, the optimal model of effectiveness is selected as each kind of complex feature module. In this stage, the optimal performance can reach as high as 70% of Matthews correlation coefficient (MCC). The second layer of construction combines the first-layer module to integrate mechanisms and the use of six machine learning methods to improve the prediction performance. This system can be improved over 10% in MCC. Finally, we analyzed the performance of our classification system using transcription factors in dimer structure and virus-infection-associated glycoprotein in trimer structure. PClass is available via a web interface at http://predictor.nchu.edu.tw/PClass/.

miR-211 regulates the expression of RRM2 in tumoral metastasis and recurrence in colorectal cancer patients with a k-ras gene mutation.

Colorectal cancer (CRC) ranks as the third-leading cause of cancer-associated mortalities in Taiwan. The expression of ribonucleotide reductase M2 (RRM2) and p53R2 is associated with tumoral malignancy and progression in several types of cancer. The aim of the present study was to determine the association of p53R2/RRM2 with the upstream expression of microRNA (miR)-211 and the association of expression levels of p53, APC and k-ras with clinical outcomes in patients with CRC. The study consisted of 192 tumor tissue samples obtained from patients with CRC. Immunohistochemistry and direct sequencing of DNA were performed to analyze p53R2/RRM2 protein expression and p53/APC/k-ras gene mutations in these samples. The expression level of miR-211 was detected by reverse transcription-quantitative polymerase chain reaction. The results showed that the expression of p53R2 was lower and that of RRM2 was higher in patients with lymph node metastasis, distant metastasis, and late-stage CRC compared with patients without lymph node metastasis, distant metastasis and early-stage CRC. A high expression of RRM2 in patients had a negative effect on overall survival (OS) and disease-free survival (DFS) in CRC. Positive expression of RRM2 was detected in tumor tissues, and expression associated with the presence of k-ras gene mutation. Furthermore, it was detected that the upstream miR-211 expression was negatively associated with RRM2 expression in tumor tissues of patients with CRC. miR-211 expression was associated with survival and tumoral recurrence in patients with k-ras mutations. The present authors suggest that the downregulation of miR-211 and overexpression of RRM2 in tumor tissues of patients with CRC could be used to predict metastases and disease prognosis, particularly in patients with k-ras gene mutations.