Molecular expression profiles of selected microRNAs in colorectal adenocarcinoma in patients from south-eastern part of Romania

The dysregulation and clinical relevance of lncRNAs MYOSLID and SFTA1P in colorectal cancer patients

BACKGROUND

Colorectal cancer (CRC) is a very common cancer worldwide. CRC is characterized by some changes in the expression of oncogenic and tumor suppressor genes. These changes are associated with dysregulation of non-coding RNAs, including long non-coding RNAs (lncRNAs). LncRNAs are heterogeneous non-coding molecules without open reading frames. LncRNAs have been established as regulators in the development of CRC and clinical biomarkers for the CRC detection. In this project, we investigated the expression changes of two new lncRNAs named SFTA1P and MYOSLID in CRC patients.

MATERIALS AND METHODS

30 samples of CRC tissue and 30 samples of normal tissue adjacent to the cancer tissue were obtained from patients. RNA extraction from tissue samples was performed using RNAX plus. ExcelRT™ Reverse Transcription Kit (SymBio, Korea) was used for cDNA synthesis. RealQ Plus 2x Master Mix Green Without ROX™ was used to perform a quantitative PCR (qPCR). REST, and SPSS software were used for statistical analysis.

RESULT

Our result demonstrated that lncRNAs MYOSLID and SFTA1P were significantly up-regulated in tumor tissues compared to healthy tissues with a fold change of 13.43 and 5.33 (P < 0.05) respectively. Based on the analysis of ROC curve, MYOSLID (AUC = 0.946, P < 0.0001, SE =0.0035) and SFTA1P (AUC = 0.800, P < 0.0001, SE = 0.059) were indicated as potential clinical hallmarks for CRC patients.

CONCLUSION

According to the results obtained from this research, lncRNAs SFTA1P and MYOSLID can be suggested as molecular biomarkers for the CRC diagnosis.

Application value of miRNA-182 as a biomarker for cancer diagnosis: a systematic review with meta-analysis

Aim: This study aims to establish the potential reliability and validity of miRNA-182 as a diagnostic tool in oncology, and hence to contribute to the decision-making process in clinical settings. Materials & methods: To further evaluate the role of miRNA-182 as a cancer biomarker, we conducted a search of the PubMed, Cochrane Library, Wanfang and China National Knowledge Infrastructure databases of existing literature. Conclusion: These results suggest that miRNA-182 could function as a potential molecular marker for cancer detection and diagnosis. The effect of miRNA-182 on tumor development should be further studied to confirm these results and add to the current understanding of its role in cancer.

TCF7L2, CASC8, and GREM1 polymorphism and colorectal cancer in south-eastern Romanian population

Colorectal cancer (CRC) is a heterogeneous disease with an increasing trend and with multiple epigenetic alterations and different molecular features, a major cause of mortality and morbidity. The Wnt/β-Catenin pathway is involved in multiple aspects of cell dynamics, architecture of developing gastrointestinal tissues, and intestinal tissue homeostasis in adults, but its aberrant activity plays an important role in every aspect of colorectal carcinogenesis. The aim of our study was to investigate the association of the TCF7L2 rs7903146, CASC8 rs6983267, and Gremlin1 (GREM1) rs16969681 polymorphism in patients with CRC without other pathologies. A case-control study conducted on 31 patients diagnosed with CRC and 30 healthy controls age and sex-matched with the patients. Real time PCR was used to determine the genotypes of rs7903146, rs698267, rs1696981. We observed no association between rs6983267 and rs16969681 polymorphism and risk of CRC and low association between TCF7L2, rs7903146, polymorphism and risk of CRC. The recessive model of the TCF7L2 rs7903146 had an OR of 1.6 (95% CI 0.058-4.414, P < .05) which means that TT genotype increased the risk and possibility of development of CRC. Our study did not confirm a significant association between TCF7L2 rs7903146, CASC8 rs6983267, and GREM1 rs16969681 with CRC, but emphasizes the possibility of existence of a high risk of CRC development in patients with TT genotype of rs7903146.

PD-L1, CD4+, and CD8+ Tumor-Infiltrating Lymphocytes (TILs) Expression Profiles in Melanoma Tumor Microenvironment Cells

(1) Background: Because melanoma is an aggressive tumor with an unfavorable prognosis, we aimed to characterize the PD-L1 expression in melanomas in association with T cell infiltrates because PD-1/PD-L1 blockade represents the target in treating melanoma strategy. (2) Methods: The immunohistochemical manual quantitative methods of PD-L1, CD4, and CD8 TILs were performed in melanoma tumor microenvironment cells. (3) Results: Most of the PD-L1 positive, expressing tumors, have a moderate score of CD4+ TILs and CD8+TILs (5-50% of tumor area) in tumoral melanoma environment cells. The PD-L1 expression in TILs was correlated with different degrees of lymphocytic infiltration described by the Clark system (X² = 8.383, p = 0.020). PD-L1 expression was observed often in melanoma cases, with more than 2-4 mm of Breslow tumor thickness being the associated parameters (X² = 9.933, p = 0.014). (4) Conclusions: PD-L1 expression represents a predictive biomarker with very good accuracy for discriminating the presence or absence of malign tumoral melanoma cells. PD-L1 expression was an independent predictor of good prognosis in patients with melanomas.

KRAS, NRAS, BRAF, PIK3CA, and AKT1 signatures in colorectal cancer patients in south-eastern Romania

Somatic mutations in the oncogenes of the epidermal growth factor receptor signaling pathway play vital roles in colorectal carcinogenesis and have been closely linked with clinical resistance to monoclonal therapy. In this study, we have analyzed the mutation frequencies of 5 genes and compared the genetic findings with clinicopathological variables in order to determine diagnostically relevant alterations and compare these findings with those of other studies In our Sanger sequencings, KRAS (exons 2, 3, and 4), NRAS (exons 2, 3, and 4), PIK3CA (exons 9 and 20), BRAF (exon 15), AKT1 (exon 2) genes, and microsatellite instability (MSI) status were analyzed using an ABI 3500 analyzer in a cohort of 58 Romanian colorectal cancer (CRC) patients who underwent surgical resection at Emergency County Clinical Hospital in Constanța, Romania. In our series, mutation rates of KRAS, BRAF, PIK3CA, and AKT1 genes were 39.63%, 8.62%, 6.88%, and 3.44%, respectively. By contrast, we did not find any tumor harboring mutation in the NRAS gene. Notably, the KRAS and PIK3CA mutations were not mutually exclusive, 1 patient harbored 2 mutations in exon2, codon 12 (Gly12Val) of KRAS and exon 20, codon 1047 (His1047Arg) of PIK3CA. The finding of our study are generally consistent with data found in the literature. Regarding to clinicopathological variables, mutation of KRAS was associated with distant metastasis at the time of diagnosis, while mutation of BRAF was significantly associated with MSI-H in contrast with MSI-L/MSS tumors. Moreover, PIK3CA mutation tends to be located in the proximal segment of the colon and to be well/moderately differentiated compared to wild-type tumors. In conclusion, the assessment of these mutations suggests that CRC patients from southeast Romania exhibit a mutation profile similar to other populations. These results could contribute to creating a better method of qualifying patients for molecularly targeted therapies and obtaining better screening strategies.

Inhibition of the cell migration, invasion and chemoresistance of colorectal cancer cells through targeting KLF3 by miR-365a-3p

Background: Metastasis and chemoresistance limit treatment efficacy of colorectal cancer (CRC) patients. MicroRNAs (miRNAs) have been believed to be candidate biomarkers for tumor cell proliferation, metastasis and chemoresistance, but the related molecular mechanisms are not clear for prognosis prediction.

Aims: We aimed to investigate the role of miR-365a-3p in metastasis and chemoresistance of CRC.

Methods: The expression levels of miR-365a-3p in clinical CRC tissues were analyzed. The effects of miR-365a-3p expression levels on tumor chemoresistance, invasion and migration were also determined. A dual luciferase reporter gene assay was used to determine the effect of miR-365a-3p on its target gene, Kruppel-like factor 3 (KLF3), and the effect of the miR-365a-3p/KLF3 axis on CRC cell chemoresistance, migration and invasion was further investigated.

Results: In patients with CRC with lymph node or distant organ metastasis or in CRC cell lines, the expression levels of miR-365a-3p were significantly downregulated. In addition, the findings of Transwell assays demonstrated that miR-365a-3p significantly suppressed CRC cell migration and invasion. The dual luciferase reporter gene assay results suggested that miR-365a-3p may play an important role in the regulation of migration, invasion and chemoresistance in CRC cells.

Conclusions: The findings of present study provided evidence to suggest that miR-365a-3p may be a potential tumor suppressor gene in CRC and may inhibit the migration, invasion and chemoresistance of CRC cells. These results suggested that targeting miR-365a-3p/KLF3 axis may represent a potential therapeutic intervention for metastatic disease in patients with CRC.

Molecular profiling of the colon cancer in South-Eastern Romania: Results from the MERCUR study

ABSTRACT

Colorectal cancer is a heterogeneous disease with multiple epigenetic alterations and different molecular features. The molecular classification is based on 2 major distinct pathways: microsatellite stable pathway and the microsatellite instability pathway. Molecular profiling of colorectal cancer provides important information regarding treatment and prognosis. Aim of the study was to assess the frequency of microsatellite instability in colon cancer and the clinicopathological characteristics of the tumors with high level of microsatellite instability (MSI-H) in our region. The secondary outcome was to assess the frequency of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations in colon cancer.The study included 129 patients with colon cancer fit for surgery. Demographic data, clinical and pathological data, immunohistochemistry staining pattern (4 mismatch repair proteins were investigated), and BRAF gene mutations were assessed. According to microsatellite instability status by polymerase chain reaction, patients were divided into 3 groups: microsatellite stable (MSS) = 108 patients, high level of microsatellite instability (MSI-H) = 15 patients and low level of microsatellite instability (MSI-L) = 6 patients. Different clinicopathological comparisons between MSS and MSI-H patients, and between MSS and MSI-L patients were performed.Microsatellite instability was found in 16.3% patients: 11.6% had MSI-H and 4.7% had MSI-L. Significantly more patients in the MSI-H group than in the MSS group were female (P = .01) and had a family history of colon cancer (P < .001). MSI-H and MSI-L groups were associated with the ascending colon location of the tumors, were mostly type G3, T2, and stage I whereas MSS tumors were mostly G2, pT3, and stage III. Overall, BRAF mutations were identified in 18/129 patients (13.9%). BRAF mutant tumors were predominantly associated with MSI-H and MSI-L tumors. Immunohistochemistry had a sensitivity of 76% and a specificity of 89% in detecting MSI tumors and an accuracy of 87.6%.The frequency of microsatellite instability in our study was 16.3%. MSI-H is a distinct molecular phenotype of colon cancer with particular features: female gender, family history of colorectal cancer, a predilection for the ascending colon, poorly differentiated, predominantly T2, and stage I. The frequency of BRAF mutations was 13.9% and mutations were more often present in the MSI tumors.

The diagnostic value of miR-92a, -143, and -145 expression levels in patients with colorectal adenocarcinoma from Romania

MicroRNAs (miRNAs) refers to a small, short non-coding RNA of endogenous class. They have shown to have an increasingly altered expression in many types of cancer, including colorectal cancer (CRC).In the present study, miRNA TaqManMGB and qRT-PCR was used to quantify the expression and clinical significance of 3 mature human miRNA in 82 pairs of colorectal adenocarcinoma tissues and normal adjacent tissue samples (NATS) collected from patients of the south-east part of Romania. Differences between CRC and NATS were analyzed using Wilcoxon test, while correlations between miRNAs expression levels and clinicopathological features were examined using non-parametric tests. In addition, the ability of selected miRNAs to function as biomarkers and, as potential indicators in CRC prognosis was also examined.When the miRNA expression was compared in CRC related NATS, miR-143, and miR-145 were significantly underexpressed (4.99 ± -1.02 vs -5.66 ± -1.66, P < .001; -4.85 ± -0.59 vs -9.27 ± -1.51, P < .001, respectively), while the pattern of miR-92a was significantly overexpressed (-5.55 ± -2.83 vs -4.92 ± -2.44, P < .001). Moreover, the expression levels of selected miRNAs were identified to be correlated with gradual increases in fold change expression with the depth of tumor invasion, lymph node invasion, and maximal increases with distant metastasis. Furthermore, the receiver operating characteristic analysis demonstrated that potential diagnostic of miR-143, miR-145, and miR-92a in discriminating CRC from NATS, with the area under the curve of 0.74, 0.85, and 0.84 respectively. The Kaplan-Meier and the log-rank test showed that a high level of miR-92a and low levels of miR-143 and miR-145 predicted poor survival rate in our cohorts.In conclusion, we can summarize that miR-145 and miR-143 are decreased, while miR-92 is increased in CRC compared to NATS, and associated with different stages of CRC pathogenesis. Thus, the expression of selected miRNAs can represent potential diagnostic and prognostic tools in patients with CRC from Romania.