Regulation of gene expression is essential for normal physiological functions; thus deregulation of gene expression is common in disease conditions. One level of regulation of gene expression is performed by noncoding RNAs, among which microRNAs (miRNA) are the best studied. Abnormal expression of these molecular players can lead to pathogenic processes such as heart disease, immune system abnormalities, and carcinogenesis, to name but a few. Of a length of 18–25 nucleotides miRNAs are involved in binding partial complementary sequences within the 3′-UTR (3′-untranslated region) of the target mRNAs. Depending on the type of neoplastic transformation, miRNAs can act both as oncogenes (oncomirs) or as tumor suppressors. Because of the great importance of miRNAs, most researches focus on either their role as biomarkers or their potential as therapeutic targets. Herein, we present the review of microRNA biology, function, and tumorigenic potential with emphasis on their role in lung cancer.

Acetylation and deacetylation are posttranslational modifications (PTMs) which affect the regulation of chromatin structure and its remodeling. Acetylation of histone 3 at lysine placed on position 18 (H3K18Ac) plays an important role in driving progression of many types of cancer, including breast, colon, lung, hepatocellular, pancreatic, prostate, and thyroid cancer. The aim of this review is to analyze and discuss the newest findings regarding the role of H3K18Ac and acetylation of other histones in carcinogenesis. We summarize the level of H3K18Ac in different cancer cell lines and analyze its association with patients’ outcomes, including overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS). Finally, we describe future perspectives of cancer therapeutic strategies based on H3K18 modifications.

Background/Aim: Ovarian cancer is the most frequent cause of death in women among gynecological cancers in Poland. MMP-2 and MMP-9 are frequently dysregulated in cancers and they are considered as potential biomarkers. Our goal was to assess the associations between MMP-2 and MMP-9 mRNA expression, clinicopathological parameters and patients' response to chemotherapy. Materials and Methods: We evaluated MMP-2 and MMP-9 mRNA expression in epithelial ovarian cancer (EOC) tissues from 44 untreated patients, four ovarian cancer cell lines, and human skin fibroblasts (HSF). The expression of both MMPs was estimated using qPCR. Results: MMP-2 expression was significantly higher (p=0.020) in EOCs sensitive to chemotherapy compared to resistant and refractory tumors. The highest MMP-2 expression was found in HSF and MMP-9 expression was the highest in EOCs (p<0.001). The expression of neither MMP was significantly associated with patients' overall survival (OS). Conclusion: MMP-2 may be engaged in early stages of ovarian carcinogenesis. MMP-2 expression in EOCs may discriminate patients with a favorable response to first line chemotherapy.

Inflammatory bowel disease (IBD) comprises ulcerative colitis (UC) and Crohn disease (CD). Similar symptoms, but different treatment procedures for both diseases require precise diagnosis. MicroRNAs (miRNAs) are major posttranscriptional players that regulate the expression of genes during the inflammation and thus could be appropriate biomarkers for differentiation between UC and CD. For this purpose, we analyzed the expression of miR-21-3p, miR-31-3p, miR-125b-1-3p, miR-146a-3p, miR-155-5p, and E-cadherin (CDH1) genes associated with IBD, in 67 tissue samples: 28 inflamed mucosa samples (n=16 UC, n=12 CD), 28 adjacent normal colonic mucosa (n=16 UC, n=12 CD), and 11 normal mucosa from healthy patients using reverse transcription real-time RT-PCR. We found all analyzed miRNAs were significantly overexpressed in UC tissue as compared to adjacent normal tissue of patients with UC, as well as to normal mucosa from healthy controls. Four miRNAs (except miR-125b-1-3p) were significantly upregulated in CD lesions as compared to adjacent normal tissue of patients with CD, and four miRNAs, except miR-146a-3p, were significantly higher in CD samples compared to normal mucosa from healthy individuals. In the CD group, we found an inverse correlation between miR-155-5p or miR-146a-3p expressions and CDH1expression in inflamed mucosa. This type of correlation was also detected for miR-213p in adjacent normal tissue and CDH1 in inflamed mucosa, as well as between miR-155-5p and CDH1 in adjacent normal tissue. Elevated miRNA expression is characteristic for IBD-mediated inflammation process and inversely correlated with CDH1 gene expression, which suggest involvement of epithelial to mesenchymal transition (EMT) in IBD development.

Platelet (PLT) indices have been proposed as potential markers in the assessment of liver fibrosis and exacerbation of liver failure. The aim of our study was to verify mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) in alcohol-related liver cirrhosis (ALC) and nonalcoholic fatty liver disease (NAFLD) patients. One hundred forty-two patients with ALC, 92 with NAFLD, and 68 in control group were enrolled in this study. Hematological indices (MPV, PCT, and PDW) and serological (indirect and direct) markers of liver fibrosis (AAR, APRI, FIB-4, GPR, PICP, PIIINP, TGF-α, PDGF-AB, laminin) were measured in each participant. MELD score in ALC patients and NAFLD fibrosis score (NFS) together with BARD score in the NAFLD group were also obtained. Results were compared between research and control groups. Then, a correlation between evaluated indices was performed in study groups. Receiver operating characteristic curves (ROCs) and area under the curve (AUC) values were applied to assess the diagnostic accuracy of measured indices. Significant increase in PDW and decrease in PCT in comparison to controls were noted in examined ALC (60.4% vs. 51.2% and 0.1% vs. 0.21%, respectively, p < 0.0001 ) and NAFLD (54.75% vs. 51.2% and 0.19 vs. 0.21%, respectively, p < 0.01 ) patients. Decreased level of MPV was observed in NAFLD group (7.85 fl vs. 8.90 fl, p < 0.0001 ). Additionally, PCT correlated with NFS ( p < 0.0001 ). Evaluated PLT indices correlated with MELD score (MPV and PDW, p < 0.001 ; PCT, p < 0.05 ). They correlated with indirect and direct markers of liver fibrosis in the whole research group, too. PCT was the parameter with the greatest diagnostic accuracy in ALC patients ( AUC = 0,839 for cutoff < 0.17 % ); in NAFLD group, it was MPV ( AUC = 0,808 for cutoff < 7.9   fl ). PCT in ALC and MPV in NAFLD can be perceived as potential diagnostic markers.