Transcript CD81-215 may be a long noncoding RNA of stromal origin with tumor-promoting role in colon cancer.

The role of tetraspanin CD81 in malignant transformation is best studied in colorectal cancer, and it appears that other transcripts beside the fully coding mRNA may also be dysregulated in malignant cells. Recent data from a comprehensive pan-cancer transcriptome analysis demonstrated differential activity of two alternative CD81 gene promoters in malignant versus nonmalignant gut mucosa. The promoter active in gut mucosa gives rise to transcripts CD81-203 and CD81-213, while the promoter active in colon and rectal cancer gives rise to transcripts CD81-205 and CD81-215. Our study aimed to explore the biomarker potential of the transcripts from the alternative CD81 gene promoters in colon cancer, as well as to investigate their structure and potential function using in silico tools. The analysis of the transcripts' expression in several colon cell lines cultivated in 2D and 3D and a set of colon cancer and healthy gut mucosa samples by qPCR and RNA sequencing suggested their low expression and stromal origin. Expression patterns in tumor and nontumor tissue along with in silico data suppose that the transcript CD81-215 may be a noncoding RNA of stromal origin with possible involvement in signaling related to malignant transformation.

SMAD4-201 transcript as a putative biomarker in colorectal cancer.

BACKGROUND: Transcripts with alternative 5'-untranslated regions (UTRs) result from the activity of alternative promoters and they can determine gene expression by influencing its stability and translational efficiency, thus executing complex regulation of developmental, physiological and pathological processes. Transcriptional regulation of human SMAD4, a key tumor suppressor deregulated in most gastrointestinal cancers, entails four alternative promoters. These promoters and alternative transcripts they generate remain unexplored as contributors to the SMAD4 deregulation in cancer. The aim of this study was to investigate the relative abundance of the transcript SMAD4-201 in colorectal cell lines and tissues in order to establish if its fluctuations may be associated with colorectal cancer (CRC). METHODS: Relative abundance of SMAD4-201 in total SMAD4 mRNA was analyzed using quantitative PCR in a set of permanent human colon cell lines and tumor and corresponding healthy tissue samples from patients with CRC. RESULTS: The relative abundance of SMAD4-201 in analyzed cell lines varied between 16 and 47%. A similar relative abundance of SMAD4-201 transcript was found in the majority of analyzed human tumor tissue samples, and it was averagely 20% lower in non-malignant in comparison to malignant tissue samples (p = 0.001). Transcript SMAD4-202 was not detectable in any of the analyzed samples, so the observed fluctuations in the composition of SMAD4 transcripts can be attributed to transcripts other than SMAD4-201 and SMAD4-202. CONCLUSION: The expression profile of SMAD4-201 in human tumor and non-tumor tissue samples may indicate the translational potential of this molecule in CRC, but further research is needed to clarify its usability as a potential biomarker for early diagnosis.

Prognostic potential of circulating miR-93-5p in patients with colorectal cancer liver metastases.

This study aimed to examine the expression pattern of tumoral and circulating miR-93-5p in patients with colorectal cancer (CRC) liver metastasis (CRLM) and to explore its predictive and prognostic potential. CRLM tissue, surrounding non-tumor liver tissue, and serum were obtained from 35 patients with CRLM. The expression pattern of tissue and circulating miR-93-5p in patients with CRLM was determined using quantitative polymerase chain reaction, using miR-16-5p for normalization. Sample-based cut-off values for CRLM and serum miR-93-5p expression were calculated using Receiver Operating Characteristic curve analysis to stratify the patients into high and low miR-93-5p expression groups which were that compared with patients' clinicopathological data, therapy response, one-year disease-free survival, and disease recurrence. Relative miR-93-5p expression was higher in CRLM in comparison to the non-metastatic liver tissue (p<0.001). CRLM miR-93-5p expression showed moderate negative correlation with carcinoembryonic antigen levels (r=-0.406; p=0.016). There were no differences in high-/low-miR-93-5p expression and therapy responders vs. non-responders, which was confirmed in vitro using metastatic and normal colonic cells SW620 and HCEC-1CT, respectively. No difference was observed in one-year recurrence-free survival in patients with high vs. low miR-93-5p expression in CRLM or serum. However, high miR-93-5p serum levels were significantly associated with early disease recurrence (p=0.035). In conclusion, miR-93-5p serum levels could be potentially used as a prognostic factor for early disease recurrence in CRLM patients.

Prognostic relevance of autophagy-related markers p62, LC3, and Beclin1 in ovarian cancer.

AIM: To analyze the expression of autophagy markers p62, LC3, and Beclin1 in ovarian cancer tissue and evaluate the prognostic potential of these markers. METHODS: The study enrolled 328 patients: 122 with epithelial ovarian carcinoma, 42 with atypical proliferative tumor, and 164 with benign epithelial ovarian tumor. The expression of p62, LC3, and Beclin1 was analyzed in central and invasive tumor segments with immunohistochemistry combined with tissue microarray. The expression levels of the analyzed markers were correlated with relevant histopathology parameters. RESULTS: The expression of all analyzed markers was most remarkable in epithelial ovarian carcinoma. There was a strong positive correlation between the expressions of p62 and LC3, while these two markers negatively correlated with Beclin1. High-grade serous carcinoma had higher p62 and LC3 levels, and lower Beclin1 levels than other tumor types. This expression profile was also observed in more advanced tumor stages. CONCLUSION: Prominent p62 and LC3 expression in combination with weak Beclin1 expression in high-grade serous carcinoma indicates potential for the application of autophagy inhibitors in patients with this tumor subtype.

SMAD7 and SMAD4 expression in colorectal cancer progression and therapy response.

Inhibitory SMAD7 and common mediator SMAD4 play crucial roles in SMAD-dependent TGF-ß signaling that is often disrupted in colorectal cancer (CRC). This study aimed to profile the expression of SMAD7 and SMAD4 in primary and metastatic CRC and to evaluate their significance in disease progression and therapy response. The expression of SMAD7 and SMAD4 genes was analyzed by quantitative real-time PCR in tissues from 35 primary and metastatic CRC patients and in vitro in 7 human cell lines originating from colon tissue. Expression levels of SMAD7 and SMAD4, as well as their ratio, were determined and their association with tumor characteristics and response to therapy were evaluated. SMAD4 level was significantly lower in tumors compared to non-tumor tissues in both primary (p = 0.001) and metastatic (p = 0.001) CRC patients, while tumor expression of SMAD7 was significantly lower from non-tumor tissue only in metastatic patients (p = 0.017). SMAD7/SMAD4 ratio was elevated in CRC primary tumor tissues and cell lines compared to corresponding non-tumor tissues and cell line, respectively (p = 0.003). SMAD7 expression was significantly elevated in primary tumor tissues obtained from responders to neoadjuvant chemoradiotherapy (nCRT) compared to non-responders (p = 0.014). Alterations of expression and ratio of SMAD7 and SMAD4 in CRC cell lines, primary rectal cancer, and liver metastasis emphasize the importance of these genes in different stages of disease progression. Differential expression of SMAD7 in responders versus non-responders to nCRT should be further investigated for its potential predictive value.

The Variants in the 3' Untranslated Region of the Matrix Metalloproteinase 9 Gene as Modulators of Treatment Outcome in Children with Asthma.

PURPOSE: The maintaining of asthma control is difficult due to high variability in response to therapy among patients. Since matrix metalloproteinase 9 (MMP9) is implicated in inflammation and remodeling of asthmatic airways, it could be associated with adequate response to asthma therapy. The aim of this study was to investigate whether variants in 3' end of the MMP9 gene are associated with clinical phenotype and responsiveness to treatment in children with asthma. METHODS: The study included 127 asthmatic children from Slovenia. Variants in the 3' end of the MMP9 gene were analyzed by direct DNA sequencing and the obtained results were correlated with clinical parameters. RESULTS: Two variants were detected, rs13925 and rs20544. For the variant rs20544, statistically significant difference in airway hyperresponsiveness (p = 0.011) and asthma control (p = 0.049) between genotypes was found. Patients with TT genotype had lower airway sensitivity, and after 12 months of treatment showed significant improvement in Asthma Control Test (ACT) scores compared to CC and CT genotype. For the variant rs13925, the association with lung function was observed. The carriers of A allele showed noticeable improvement of lung function after the first 6 months of treatment in comparison to the carriers of G allele (p = 0.046). CONCLUSION: The main finding of our study is the association of MMP9 genotypes rs20544 TT and rs13925 AA and AG with better asthma control, and indirectly better response to treatment. Based on these results, MMP9 deserves further research as a potential predictive biomarker for asthma.

Polymorphism RAD51 172G > T in Serbian patients with colorectal cancer.

PURPOSE: The RAD51 gene plays an important role in homologous strand exchange in DNA repair. Two common single nucleotide polymorphisms in this gene, 135G>C and 172G>T, were associated with altered gene transcription. While 135G>C was already linked to breast and colorectal cancers in certain populations, 172G>T is far less investigated, although sporadic studies showed it could be a prognostic factor for some cancer lesions. The purpose of this study was to investigate RAD51 172G>T polymorphism in Serbian population, its association with colorectal carcinoma, as well as correlation with disease characteristics and response to neoadjuvant chemoradiotherapy. METHODS: The 172G>T polymorphism was evaluated by PCR-RFLP method in blood samples of 209 colorectal cancer patients and 43 healthy subjects who served as controls. The distribution of genotypes was also analyzed in respect to several tumor characteristics in cases where histopathological data were available. RESULTS: A significant association between the RAD51 172G>T polymoprhism and desmoplastic reaction of colorectal cancer was demonstrated. The 172G allele was found to be significantly more frequent in patients with more intensive desmoplastic response of the tumor tissue. CONCLUSIONS: The results of our study suggest that the 172T allele of RAD51 may be a favorable prognostic factor in Serbian patients with colorectal cancer, although larger prospective studies are required to confirm this finding.

Genetic analysis and allele-specific expression of SMAD7 3'UTR variants in human colorectal cancer reveal a novel somatic variant exhibiting allelic imbalance.

BACKGROUND: Considering the impact of SMAD7 deregulation in colorectal cancer (CRC) progression and the significance of single nucleotide variant (SNV)-mediated disruptions of microRNA (miRNA)-dependent regulation for cancer susceptibility, our study aimed to analyze genetic variation in the SMAD7 3' untranslated region ( 3'UTR) in CRC, measure differences in allelic mRNA expression, and evaluate its interference with miRNA-mediated post-transcriptional regulation. PATIENTS AND METHODS: This study included 80 patients with different CRC stages and six human colon cancer cell lines of various histological origins. SMAD7 3'UTR was analyzed by direct sequencing, followed by the relative quantification of differential allelic expression of detected variants by allele-specific qRT-PCR. In silico tools were employed for predictions of regulatory consequences of detected variants. RESULTS: A total of four different SNVs in one cell line and nine patients were found, among which were a novel somatic point variant and three already known germline variants (rs16950113, rs1050799536, and rs1043778717). All evaluated SNVs exhibited variable extents of allelic imbalance in expression. In silico analysis predicted significant effects of SNVs on miRNA binding efficiency, with each SNV disrupting existing and creating new target sites for one or more miRNAs. CONCLUSION: Imbalance observed in the expression of SNV alleles altering miRNA binding suggests that all investigated SNVs are potential contributing factors impacting SMAD7 expression regulation in CRC that further studies should investigate.

Effects of Chemotherapy for Metastatic Colorectal Cancer on the TGF-ß Signaling and Related miRNAs hsa-miR-17-5p, hsa-miR-21-5p and hsa-miR-93-5p.

Metastatic colorectal cancer (mCRC) patients are treated with standard chemotherapeutic drugs in the form of FOLFOX and FOLFIRI regimens. There are no reliable markers that could predict response to chemotherapy for mCRC. TGF-ß signaling which interacts with microRNA (miRNA) network has important roles in tumor progression and chemotherapy resistance, thus the interplay between TGF-ß signaling and miRNAs could be crucial for treatment response. The aim of this study was to analyze the effect of chemotherapy for mCRC on TGF-ß signaling and related miRNAs. Hsa-miR-17-5p, hsa-miR-21-5p and hsa-miR-93-5p were selected out of 316 miRNAs with multiple targets within the TGF-ß signaling by in silico analysis. SW620 cells were treated with chemotherapeutic drugs for mCRC for 1, 3 and 6 days and expression of selected miRNAs, PAI-1, CDH1 and VIM was measured. Expression of TGF-ß signaling-related hsa-miR-17-5p, hsa-miR-21-5p and hsa-miR-93-5p was time-dependently altered in SW620 cells treated with chemotherapeutics for mCRC. The expression of hsa-miR-93-5p remained downregulated after 6 days under combined treatments FOX and FIRI as well as the hsa-miR-17-5p expression under FIRI. Chemotherapy regimens for mCRC increased expression of a major TGF-ß signaling target gene PAI-1, independently of the selected miRNAs expression. These treatments also increased the expression of epithelial-mesenchymal transition (EMT) markers CDH1 and VIM on day 3 resulting in decrease of mesenchymal-like characteristics. However, their expression returned close to basal level on day 6. In conclusion, after initial response to chemotherapeutic drugs SW620 cells start to return close to the basal mesenchymal state while the long-term downregulated expression pattern of hsa-miR-93-5p and hsa-miR-17-5p makes them candidates worth testing as biomarkers for monitoring combined chemotherapeutic treatments therapy response in mCRC patients.

Bacterial Nanocellulose as a Scaffold for In Vitro Cell Migration Assay.

Bacterial nanocellulose (BNC) stands out among polymers as a promising biomaterial due to its mechanical strength, hydrophilicity, biocompatibility, biodegradability, low toxicity and renewability. The use of scaffolds based on BNC for 3D cell culture has been previously demonstrated. The study exploited excellent properties of the BNC to develop an efficient and low-cost in vitro cell migration assay. The BNC scaffold was introduced into a cell culture 24 h after the SW480 cells were seeded, and cells were allowed to enter the scaffold within the next 24-48 h. The cells were stained with different fluorophores either before or after the introduction of the scaffold in the culture. Untreated cells were observed to enter the BNC scaffold in significant numbers, form clusters and retain a high viability after 48 h. To validate the assay's usability for drug development, the treatments of SW480 cells were performed using aspirin, an agent known to reduce the migratory potential of this cell line in culture. This study demonstrates the application of BNC as a scaffold for cell migration testing as a low-cost alternative to commercial assays based on the Boyden chamber principle. The assay could be further developed for routine use in cancer research and anticancer drug development.

Biomarkers of Uremic Cardiotoxicity.

Cardiovascular (CV) morbidity and mortality increase along with the progression of chronic kidney disease (CKD). The potential novel biomarkers of cardiotoxicity have been tested with the aim of the early detection of patients at high CV risk, and among them are markers of inflammation, oxidative stress, acute renal injury, and microRNAs. The study analyzed biomarkers in non-dialysis-dependent (NDD; stage 3a-4 CKD) and dialysis-dependent (DD) CKD patients. The prospective cohort study included 87 patients who were followed for 18 months, during which period newly occurred CV events were recorded. Cox regression analysis confirmed serum albumin, urea, interventricular septum thickness diameter (IVST), the use of calcium antagonist, and erythropoiesis-stimulating agent to be significant predictors of CV outcome. No significant difference was observed in biomarkers of inflammation, oxidative stress, acute kidney injury (IL-18, CRP, ferritin, IMA, SOD, NGAL, and KIM-1), and miR-133a, in regards to the presence/absence of CV event, CV death, and left ventricular hypertrophy. Serum albumin, urea, IVST, and the use of calcium antagonist and erythropoiesis-stimulating agents were confirmed to be factors associated with CV events in CKD patients. Apart from traditional risk factors, new research is needed to define novel and reliable biomarkers of cardiotoxicity in CKD patients.

Influence of the Polymorphism C-509T in the TGFB1 Gene Promoter on the Response to Montelukast.

Transforming growth factor beta 1 (TGFB1) is a multifunctional cytokine with a key role in asthma airway inflammation and remodeling. Since elevated levels of this cytokine in airways might be associated with response to asthma therapy, the aim of this study was to investigate whether the presence of the polymorphism C-509T in the promoter of the TGFB1 gene is associated with response to montelukast. A group of 102 asthmatic patients was genotyped for the presence of the C-509T polymorphism by DNA sequencing and subjected to induced sputum sampling. Cells from sputum samples and BEAS 2B cells were treated with montelukast and endogenous TGFB1 expression was measured by quantitative real-time polymerase chain reaction. The promoter activity was analyzed by luciferase assays in BEAS 2B cells transfected with constructs carrying variants -509C and -509T of the TGFB1 gene promoter. After treatment with montelukast, the decrease in TGFB1 gene expression was greater for the -509TT genotype (58.9%) than for the -509CC and -509CT genotypes (49.6% and 31.8%, respectively) (P = 0.071). In BEAS 2B cells, expression of endogenous TGFB1 was reduced by about 27% after montelukast treatment, while luciferase activity of both promoter variants was increased after montelukast treatment (-509C allele: 48.3%, P = 0.060; and -509T allele: 100.5%, P = 0.062). A more intensive response was registered in the promoter containing the -509T allele, which had 135% higher activity than the -509C variant (P = 0.035). This study showed that the presence of the -509T allele in the TGFB1 promoter might modulate effects of montelukast on TGFB1 gene expression, but future studies are necessary, taking into consideration other genetic and nongenetic factors. It is of potential importance for clinical management of asthma to clarify the influence of the C-509T polymorphism on the response to treatment with montelukast.

TGFB1 Gene Promoter Polymorphisms in Serbian Asthmatics.

BACKGROUND: Asthma is a chronic respiratory disease caused by a combination of genetic and environmental factors. Transforming growth factor beta 1 (TGFB1) is a multifunctional cytokine that plays an important role in airway remodeling in asthma. OBJECTIVES: The aim of this study was to analyze common TGFB1 gene promoter polymorphisms C-509T and G-800A in Serbian asthmatics and to investigate their association with exacerbations. MATERIAL AND METHODS: The study involved 102 asthmatics and 58 healthy individuals from Serbia, age and gender matched. An analysis of the TGFB1 promoter was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: For polymorphism C-509T a significant difference in the allele frequency was observed between the patients and the controls (p = 0.011), while the genotype distribution was similar in the analyzed groups, with statistical significance near the borderline (p = 0.061). For the polymorphism G-800A no difference was observed between the groups. The frequency of the -509TT genotype was higher in patients with exacerbations compared to patients without exacerbations (36.4% vs. 17.0%), with statistical significance near the borderline (p = 0.080). CONCLUSIONS: The results suggest that polymorphism C-509T may be associated with asthma and disease exacerbations, while G-800A is not significant for the etiology and clinical course of the disease. These findings should be confirmed in a larger study group, and since the TGFB1 promoter is highly complex and very responsive to environmental factors, future studies should also take other genetic and non-genetic factors into consideration.