Analysis on expression level and diagnostic value of miR-19 and miR-21 in peripheral blood of patients with undifferentiated lung cancer

Contributions of Circulating microRNAs for Early Detection of Lung Cancer

There is unmet need to develop circulating biomarkers that would enable earlier interception of lung cancer when more effective treatment options are available. Here, a set of 30 miRNAs, selected from a review of the published literature were assessed for their predictive performance in identifying lung cancer cases in the pre-diagnostic setting. The 30 miRNAs were assayed using sera collected from 102 individuals diagnosed with lung cancer within one year following blood draw and 212 controls matched for age, sex, and smoking status. The additive performance of top-performing miRNA candidates in combination with a previously validated four-protein marker panel (4MP) consisting of the precursor form of surfactant protein B (Pro-SFTPB), cancer antigen 125 (CA125), carcinoembryonic antigen (CEA) and cytokeratin-19 fragment (CYFRA21-1) was additionally assessed. Of the 30 miRNAs evaluated, five (miR-320a-3p, miR-210-3p, miR-92a-3p, miR-21-5p, and miR-140-3p) were statistically significantly (Wilcoxon rank sum test p < 0.05) elevated in case sera compared to controls, with individual AUCs ranging from 0.57−0.62. Compared to the 4MP alone, the combination of 3-miRNAs + 4MP improved sensitivity at 95% specificity by 19.1% ((95% CI of difference 0.0−28.6); two-sided p: 0.006). Our findings demonstrate utility for miRNAs for early detection of lung cancer in combination with a four-protein marker panel.

Role of miRNA-19a in Cancer Diagnosis and Poor Prognosis

Cancer is a multifactorial disease that affects millions of people every year and is one of the most common causes of death in the world. The high mortality rate is very often linked to late diagnosis; in fact, nowadays there are a lack of efficient and specific markers for the early diagnosis and prognosis of cancer. In recent years, the discovery of new diagnostic markers, including microRNAs (miRNAs), has been an important turning point for cancer research. miRNAs are small, endogenous, non-coding RNAs that regulate gene expression. Compelling evidence has showed that many miRNAs are aberrantly expressed in human carcinomas and can act with either tumor-promoting or tumor-suppressing functions. miR-19a is one of the most investigated miRNAs, whose dysregulated expression is involved in different types of tumors and has been potentially associated with the prognosis of cancer patients. The aim of this review is to investigate the role of miR-19a in cancer, highlighting its involvement in cell proliferation, cell growth, cell death, tissue invasion and migration, as well as in angiogenesis. On these bases, miR-19a could prove to be truly useful as a potential diagnostic, prognostic, and therapeutic marker.

TAp63α Is Involved in Tobacco Smoke-Induced Lung Cancer EMT and the Anti-cancer Activity of Curcumin via miR-19 Transcriptional Suppression

As a key risk factor for lung cancer, tobacco smoke (TS) influences several cellular processes, including epithelial-mesenchymal transition (EMT). TAp63α is a crucial transcription factor involved in tumor progression. The present study was designed to investigate the potential role and underlying mechanisms of TAp63α in TS-induced lung cancer EMT. We found that compared to normal tissues, the tumor tissues collected from lung cancer patients showed a lower level of TAp63α expression, along with downregulated E-cadherin expression and upregulated Vimentin expression. Results of treatment with TAp63α and TAp63α siRNA as well as with tumor growth factor-β (TGF-β) showed that TAp63α acted as a tumor suppressor gene, and its upregulated expression suppressed lung cancer EMT. Significantly, TS exposure altered expression of EMT-related markers, enhanced cell migratory and invasive capacities, and decreased the TAp63α expression level in lung cancer cells. Overexpression of TAp63α significantly alleviated TS-stimulated lung cancer EMT. Mechanistically, TAp63α expression transcriptionally reduced the miR-19 level, which resulted in the suppression of lung cancer EMT. Additionally, as a natural compound possessing anti-cancer effects, curcumin inhibited TS-induced lung cancer EMT by increasing TAp63α expression and reducing miR-19 expression. Collectively, our results indicate that TAp63α inhibits TS-induced lung cancer EMT via transcriptionally suppressing miR-19 and the inhibitory effect of TAp63α on miR-19 mediates the anti-cancer action of curcumin. These findings provide new insights into novel targets for lung cancer prevention.

The diagnostic role of microRNA 21 in patients with nonsmall cell lung cancer: An exploratory study

Background:

Although histopathological examination of the biopsy specimen is the gold standard for the diagnosis of non small cell lung cancer (NSCLC), a blood-based noninvasive test (liquid biopsy) may prove to be helpful in patients with repeatedly negative biopsy or for response assessment following neoadjuvant therapy. The present study was conducted to explore the diagnostic value of circulating serum microRNA (miRNA) 21 in patients with NSCLC.

Methods:

This case–control analytical study was carried out in a tertiary care teaching hospital in Northern India. The study consisted of 30 cases of biopsy-proven NSCLC and 30 controls. Serum miRNA-21 expression levels were estimated by extracting total RNA from the serum sample, reverse transcribing it to cDNA and quantified in relation to U6 reference miRNA.

Results:

A total of 30 patients with NSCLC and 30 controls were included in the study. The subjects were comparable in two groups with reference to age, gender, and smoking. Pathological types were adenocarcinoma in 19 (63.3%) and squamous cell carcinoma in 11 (36.6%) patients. Majority of the patients had advanced disease-AJCC stage III in 15 patients and AJCC Stage IV in 13 patients; two patients had stage II disease. There was a significant upregulation of serum miRNA 21 gene expression in the patients with lung cancer compared to controls (median fold change, 3.39 vs. −2.81, P = 0.00). A fourfold change in serum miRNA 21 is significantly associated with the diagnosis of NSCLC with a high specificity of 97% and area under curve of 0.84 (95% confidence interval of 0.74–0.94).

Conclusion:

Estimation of serum miRNA 21 expression has potential to be used as liquid biopsy for the diagnosis of NSCLC. Further studies with large sample sizes are warranted to confirm the diagnostic accuracy of serum miRNA 21 expression.