Ląstelės biologija : bendrasis vadovėlis

Su bibliogrVilniaus universitetasVytauto Didžiojo universiteta

Future Screening Prospects for Ovarian Cancer

Current diagnostic tools used in clinical practice such as transvaginal ultrasound, CA 125, and HE4 are not sensitive and specific enough to diagnose OC in the early stages. A lack of early symptoms and an effective asymptomatic population screening strategy leads to a poor prognosis in OC. New diagnostic and screening methods are urgently needed for early OC diagnosis. Liquid biopsies have been considered as a new noninvasive and promising method, using plasma/serum, uterine lavage, and urine samples for early cancer detection. We analyzed recent studies on molecular biomarkers with specific emphasis on liquid biopsy methods and diagnostic efficacy for OC through the detection of circulating tumor cells, circulating cell-free DNA, small noncoding RNAs, and tumor-educated platelets

The Emerging Role of Chromatin Remodeling Complexes in Ovarian Cancer

Ovarian cancer (OC) is the fifth leading cause of women’s death from cancers. The high mortality rate is attributed to the late presence of the disease and the lack of modern diagnostic tools, including molecular biomarkers. Moreover, OC is a highly heterogeneous disease, which contributes to early treatment failure. Thus, exploring OC molecular mechanisms could significantly enhance our understanding of the disease and provide new treatment options. Chromatin remodeling complexes (CRCs) are ATP-dependent molecular machines responsible for chromatin reorganization and involved in many DNA-related processes, including transcriptional regulation, replication, and reparation. Dysregulation of chromatin remodeling machinery may be related to cancer development and chemoresistance in OC. Some forms of OC and other gynecologic diseases have been associated with mutations in specific CRC genes. Most notably, ARID1A in endometriosis-related OC, SMARCA4, and SMARCB1 in hypercalcemic type small cell ovarian carcinoma (SCCOHT), ACTL6A, CHRAC1, RSF1 amplification in high-grade serous OC. Here we review the available literature on CRCs’ involvement in OC to improve our understanding of its development and investigate CRCs as possible biomarkers and treatment targets for OC

Detection of miRNAs in urine of prostate cancer patients

Background and aim: Prostate cancer (PCa) is the second most prevalent oncologic disease among men worldwide. Expression of various transcripts, including miRNAs, is markedly deregulated in cancerous prostate tissue. This study aimed at identifying a PCa-specific expression profile of miRNAs for subsequent use in noninvasive diagnostics. Materials and methods: MiRNA expression was profiled in 13 PCa tissues using human miRNA microarrays. Highly expressed miRNAs were selected for the analysis in urine of patients with PCa (N = 143) and benign prostate hyperplasia (BPH; N = 23) by means of real time PCR, while miRNAs showing the expression differences in relation to clinical variables were further analyzed in 52 PCa and 12 noncancerous prostate tissues (NPT) on TaqMan Low Density Arrays (TLDA). Results: Analysis of miRNA expression in prostate tissue linked miR-95 to aggressive form of PCa. This miRNA was up-regulated in high grade (P = 0.041), the TMPRSS2-ERG fusionpositive tumors (P = 0.026), and in patients with subsequently developed biochemical recurrence (BCR; P = 0.054) after radical prostatectomy. MiRNAs highly expressed in PCa tissues were also detectable in urine from PCa patients. Moreover, the urinary levels of miR- 21 had significant discriminatory power (P = 0.010) to separate PCa patients from BPH, while the combined analysis of urinary miR-19a and miR-19b was prognostic for BCR. In PCa, the diagnostic potential of urinary miRNA panel (miR-21, miR-19a, and miR-19b) was higher than that of the PSA test (AUC = 0.738 vs. AUC = 0.514). Conclusions: Measurement of urinary levels of PCa-specific miRNAs could assist in more specific detection of PCa and prediction of BCR

Uterine Cavity Lavage Mutation Analysis in Lithuanian Ovarian Cancer Patients

Background: Type II ovarian cancer (OC) is generally diagnosed at an advanced stage, translating into a poor survival rate. Current screening methods for OC have failed to demonstrate a reduction in mortality. The uterine lavage technique has been used to detect tumor-specific TP53 mutations from cells presumably shed from high-grade serous ovarian cancer (HGSOC). We aimed to pilot whether the detection of TP53 mutation in uterine cavity lavage can be used as a diagnostic method for HGSOC using an expanded gene panel. Methods: In this study 90, uterine lavage and 46 paired biopsy samples were analyzed using next-generation sequencing (NGS) targeting TP53 as well as five additional OC-related genes: BRCA1, BRCA2, PI3KCA, PTEN, and KRAS. Results: Uterine lavage was successfully applied to all patients, and 56 mutations were detected overall. TP53 mutations were detected in 27% (10/37) of cases of type HGSOC; BRCA1 and BRCA2 mutations were also frequent in this group (46%; 17/37). Overall concordance between tissue and liquid biopsy samples was 65.2%. Conclusion: Uterine lavage TP53 mutations in combination with other biomarkers could be a useful tool for the detection of lowly invasive HGSOC

Molecular features of doxorubicin-resistance development in colorectal cancer CX-1 cell line

Background and aim: Resistance to chemotherapy is the key obstacle to the effective treat- ment of various cancers. Accumulating evidence suggests significant involvement of the epithelial-to-mesenchymal transition (EMT) in the chemoresistance of most cancer types. This study aimed at analyzing the gene expression profile of doxorubicin (DOX)-resistant colorectal cancer cells CX-1. Materials and methods: DOX-resistant CX-1 cell sublines were acquired by stepwise increment of DOX concentrations in cell growth media. Global gene expression profiling was performed using human gene expression microarrays. The expression levels of individual genes were assessed by means of quantitative PCR (qPCR), while the DNA methylation pattern of several selected genes was determined by methylation-specific PCR. Results: Four DOX-resistant CX-1 sublines were established as a valuable tool for cell chemoresistance studies. Altered expression of the EMT, cell adhesion and motility, and chemoresistance-related genes was observed in DOX-resistant cells by genome-wide gene expression analysis. Besides, early and significant upregulation of the key EMT genes ZEB1 (5.8×; P < 0.001) and CDH2 (6.2×; P = 0.044) was identified by qPCR, with subsequent activation of drug transporter gene ABCC1 (3.3×; P = 0.007) and cell stemness gene NANOG (2.4×; P = 0.008). Downregulation of TET1 (2.1×; P = 0.041) and changes in the methylation status of the p16 gene were also involved in the acquisition of cell resistance to DOX

High-Resolution Melting-Based Quantitative Analysis of RASSF1 Methylation in Breast Cancer

Background and Objective. Breast cancer is the leading cause of death from cancer among women worldwide. The aberrant promoter methylation of tumor suppressor genes is a typical epigenetic alteration for breast cancer and can be detected in early carcinogenesis. High-throughput and cost-effective methods are needed for the early and sensitive detection of epigenetic changes in clinical material. The main purpose of our study was to optimize a high-resolution melting (HRM) assay for the reliable and quantitative assessment of RASSF1 gene methylation, which is considered one of the earliest epigenetic alterations in breast cancer. Material and Methods. A total of 76 breast carcinomas and 10 noncancerous breast tissues were studied by means of HRM and compared with the results obtained by means of quantitative methylation-specific polymerase chain reaction (QMSP) and methylation-specific polymerase chain reaction (MSP). Results. Both quantitative methods, HRM and QMSP, showed a similar specificity and sensitivity for the detection of RASSF1 methylation in breast cancer (about 80% and 70%, respectively). In breast cancer, the mean methylation intensity of RASSF1 was 42.5% and 48.6% according to HRM and QMSP, respectively. Both methods detected low levels of methylation (less than 5%) in noncancerous breast tissues. In comparison with quantitative methods, MSP showed a lower sensitivity (70%), but a higher specificity (80%) for the detection of RASSF1 methylation in breast cancer. Conclusions. HRM is as a simple, cost-effective method for the reliable high-throughput quantification of DNA methylation in clinical material

CDKN2A lokuso hipermetilinimo tyrimai kapiliarinėse hemangioblastomose, feochromocitomose ir gliomose

Background. Both capillary hemangioblastoma (CHB) and pheochromocytoma (PCC) are rare, usually benign tumours occurring sporadically or as part of familial cancer syndromes. The genetic background of most of the inherited cases is well established, but the molecular causes of sporadic cases remains poorly characterized. To better understand the molecular mechanisms of CHB and PCC pathogenesis, we analysed the genetic and epigenetic alterations of the p16 and p14 genes at the CDKN2A locus. Materials and methods. Aberrant methylation of the p16 and p14 genes was analysed in 16 cases with CHB or PCC by means of methylation-specific PCR. The differential polymerase chain reaction was used to prove the occurrence of the genetic deletion of p16. For comparison, 28 cases of glioma - a highly malignant tumour of the brain – was included into the study. Results. Data of our study show that gene p16 is hypermethylated in 25% of CHBs and in 25% of PCCs, while in gliomas this alteration is more frequent (35%) and predominantly occurs in low-grade tumours (67%). Frequent hypermethylation of the p14 gene was observed in PCCs (50%) and CHBs (37.5%), but was less prevalent in gliomas (26%). When all alterations in the CDKN2A locus were considered, including hypermethylation of p16 and p14, and genetic deletion of p16, 75% of PCC, 62.5% of CHB, and 64% of gliomas had at least one alteration of this locus. Conclusions. Our study adds new data to understanding the involvement of the CDKN2A locus in the pathogenesis of CHB and PCC - two of the most common VHLrelated tumours. Furthermore, aberrant methylation in the CDKN2A locus is also frequent in gliomas

Molecular features of doxorubicin-resistance development in colorectal cancer CX-1 cell line

eISSN 1648-9144Background and aim: Resistance to chemotherapy is the key obstacle to the effective treatment of various cancers. Accumulating evidence suggests significant involvement of the epithelial-to-mesenchymal transition (EMT) in the chemoresistance of most cancer types. This study aimed at analyzing the gene expression profile of doxorubicin (DOX)-resistant colorectal cancer cells CX-1. Materials and methods: DOX-resistant CX-1 cell sublines were acquired by stepwise increment of DOX concentrations in cell growth media. Global gene expression profiling was performed using human gene expression microarrays. The expression levels of individual genes were assessed by means of quantitative PCR (qPCR), while the DNA methylation pattern of several selected genes was determined by methylation-specific PCR. Results: Four DOX-resistant CX-1 sublines were established as a valuable tool for cell chemoresistance studies. Altered expression of the EMT, cell adhesion and motility, and chemoresistance-related genes was observed in DOX-resistant cells by genome-wide gene expression analysis. Besides, early and significant upregulation of the key EMT genes ZEB1 (5.8 ; P < 0.001) and CDH2 (6.2 ; P = 0.044) was identified by qPCR, with subsequent activation of drug transporter gene ABCC1 (3.3 ; P = 0.007) and cell stemness gene NANOG (2.4 ; P = 0.008). Downregulation of TET1 (2.1 ; P = 0.041) and changes in the methylation status of the p16 gene were also involved in the acquisition of cell resistance to DOXBiochemijos katedraGamtos mokslų fakultetasNacionalinis vėžio institutasVilniaus universitetasVytauto Didžiojo universiteta

Clinical Significance of ADAMTS19, BMP7, SIM1, and SFRP1 Promoter Methylation in Renal Clear Cell Carcinoma

Background: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney tumors, accounting for the majority of deaths from genitourinary cancers. The currently used nomograms for predicting patient outcomes are based on clinical-pathological characteristics only; however, a significant number of ccRCC survivors with similar radiological and histological features still demonstrate a different clinical course of the disease. This study aimed at the identification of novel DNA methylation biomarkers for the monitoring of patients with ccRCC. Methods: Gene expression profiling by SurePrint G3 Human GE 8×60K Microarrays was performed in 4 ccRCC tissues and adjacent non-cancerous renal tissue (NRT) samples. Four down-regulated genes were selected for further DNA methylation status analysis in 123 ccRCC and 45 NRT samples using methylation-specific PCR (MSP). Results: DNA methylation changes of ADAMTS19, BMP7, SIM1, and SFRP1 were cancer-specific with significantly (P<0.050) higher methylation frequency (37%, 20%, 18%, and 42%, respectively) in tumor tissues. The methylated status of at least one gene was significantly related to various clinical-pathological parameters, including tumor size, Fuhrman and WHO/ISUP grades, intravascular invasion, and necrosis. Moreover, the methylated status of multimarker panel ADAMTS19, BMP7 & SFRP1 was predictive for poorer overall survival (HR, 4.11; 95% CI, 1.22-13.86). Conclusion: In conclusion, DNA methylation of the three-gene panel consisting of ADAMTS19, BMP7 & SFRP1 supposedly predicts the outcome of patients diagnosed with ccRCC and possibly might be used to enrich the current prognostic tools