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Background: Our previous study has identified variant rs745430558 in the SMAD4 gene promoter as potential biomarker for adenocarcinoma of the pancreas. The allele delTT (10T instead of 12T) was present in malignant pancreatic tissue with a prevalence of 88%. As analysis of cfDNA in liquid biopsy represents a noninvasive approach for the diagnosis and monitoring of malignancies, the aim of this study was to determine the presence of 12T and 10T alleles in the peripheral blood of patients with suspected pancreatic malignancy. Material and Methods: The study was performed using cell-free DNA (cfDNA) isolated from the serum of 15 patients with morphological alterations of the pancreas. The presence of 12T and 10T alleles was assessed by allele specific quantitative real-time PCR. Results: Of 15 analyzed samples, 13 were diagnosed with adenocarcinoma of the pancreas (AcP), 1 with neuroendocrine tumor (NET), and 1 with pancreatitis. The 10T allele was present in 84.7% of cases with AcP and also in the sample from the patient with NET. In patient with pancreatitis only the 12T allele was detected. Conclusion: Our research has shown that the results of liquid biopsy of patients with AcP are in agreement with tissue specimens analysis. Targeted detection of the rs745430558 10T variant in patients with suspected pancreatic malignancies could be a potential biomarker for diagnosis of AcP in the future.

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 miRNAmediated 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.

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 lt 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.

Purpose: There are limited data on expression of epithelial-mesenchymal transition (EMT) markers in patients with colorectal liver metastases (CRLM). The study aim was to evaluate the expression and prognostic significance of E-cadherin (CDH1), fibronectin (FN1) and vimentin (VIM) in patients with CRLM after curative-intent liver resection. Patients and Methods: Thirty patients with CRLM managed by curative-intent liver resection were included in this prospective pilot study. Blood samples, colorectal liver metastases and surrounding non-tumor liver tissue were collected. Expression of CDH1, FN1 and VIM was analyzed by quantitative real-time polymerase chain reaction. Expression in CRLM and non-tumor liver tissue was compared, while expression in serum was correlated with CRLM expression. One-year recurrence-free survival was compared between patients with low and high CDH1, FN1 and VIM expression. Results: The expression of CDH1 was similar in CRLM and non-tumor liver tissues, while FN1 and VIM expression was significantly lower in metastatic tissue (P=0.003 and pP lt 0.001, respectively). Serum expression of CDH1 and VIM was detected in 66.7% and 93.3% of patients, respectively, while FN1 was not detected in any of the patients. The correlation of CDH1 and VIM expression between CRLM and serum was not statistically significant. Decreased CDH1 expression in CRLM and decreased VIM expression in serum were associated with early recurrence after surgical treatment of CRLM. Conclusion: Lower expression of CDH1 in CRLM and lower serum expression of VIM were found to be associated with early recurrence after liver resection for CRLM.