Tumor microRNA profile and prognostic value for lymph node metastasis in oral squamous cell carcinoma patients

Relevance of micro-RNAs and their targets as a diagnostic and prognostic marker in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) ranks sixth among all cancers in the world, affecting various sites of the oral cavity with associated several risk factors. High mortality has been associated with the presence of metastasis during the time of diagnosis and an increase in therapeutic relapses. Micro-RNAs (miRNAs) are a group of small non-coding RNAs with salient roles in the initiation and progression of cancer. The tumorigenesis of OSCC is associated with the dysregulation of several miRNAs. MicroRNAs are an area of recent interest, and numerous studies have been reported and are being undertaken to identify their role in diagnostic and prognostic value for oral cancers. Most of the miRNA processing machinery is considered to be either up-/down-regulated in OSCC, but the underlying mechanism of miRNA dysregulation and their activity as either a tumour suppressor or an oncogene in oral carcinogenesis is not yet clear. The article presents a concise review of the available current literature regarding the various miRNAs' signatures in OSCC and their role as diagnostic/prognostic biomarkers.

Dysregulation of miR-21-5p, miR-93-5p, miR-200c-3p and miR-205-5p in Oral Squamous Cell Carcinoma: A Potential Biomarkers Panel?

Oral squamous cell carcinoma (OSCC) is considered the sixth most common cancer worldwide. To reduce the high mortality of the disease, sensitive and specific diagnostic and prognostic biomarkers are urgently needed. Non-coding RNA, microRNAs (miRNAs), which are short length non-coding transcripts, or long non-coding RNA (lncRNA) seem to be potential biomarkers, considering that they have an important role in regulation of cell fate being involved in a wide range of biological processes. Literature data emphasized the important role of these transcripts as a biomarker for diagnosis and prognosis in oral squamous cell carcinoma. Therefore, we have evaluated the expression levels of a panel of four miRNAs (miR-21-5p, miR-93-5p, miR-200c-3p and miR-205-5p) and H19, MALAT1 by quantitative real-time PCR (qRT-PCR) from 33 fresh frozen tissues and 33 normal adjacent tissues. Our date revealed miR-21-5p and miR-93-5p to be upregulated, while miR-200c-3p and miR-205-5p to be downregulated. Regarding the long non-coding RNAs, H19 and MALAT1, were also downregulated. We also investigated the expression of BCL2, which is another important gene correlated to non-coding RNAs investigated by as, and it was also under-expressed. Additional validation step at protein level was done for KI67, TP53 and BCL2. In our patient cohort no correlation with clinical stage and smoking status was observed. The results of the present study indicated the important role of miR-21-5p, miR-93-5p, miR-200c-3p, miR-205-5p and H19 in OSCC. Differential expression of these transcripts at sub-sites, may serve as a diagnostic marker with further elaboration on a larger sample size. Additional studies should be conducted to confirm the results, particularly the interconnection with coding and non-coding genes.

A robust and interpretable gene signature for predicting the lymph node status of primary T1/T2 oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma (OSCC) affects more than 30 000 individuals in the United States annually, with smoking and alcohol consumption being the main risk factors. Management of early-stage tumors usually includes surgical resection followed by postoperative radiotherapy in certain cases. The cervical lymph nodes (LNs) are the most common site for local metastasis, and elective neck dissection is usually performed if the primary tumor thickness is greater than 3.5 mm. However, postoperative histological examination often reveals that many patients with early-stage disease are negative for neck nodal metastasis, posing a pressing need for improved risk stratification to either avoid overtreatment or prevent the disease progression. To this end, we aimed to identify a primary tumor gene signature that can accurately predict cervical LN metastasis in patients with early-stage OSCC. Using gene expression profiles from 189 samples, we trained K-top scoring pairs models and identified six gene pairs that can distinguish primary tumors with nodal metastasis from those without metastasis. The signature was further validated on an independent cohort of 35 patients using real-time polymerase chain reaction (PCR) in which it achieved an area under the receiver operating characteristic (ROC) curve and accuracy of 90% and 91%, respectively. These results indicate that such signature holds promise as a quick and cost effective method for detecting patients at high risk of developing cervical LN metastasis, and may be potentially used to guide the neck treatment regimen in early-stage OSCC.

Quantitative nuclear phenotype signatures predict nodal disease in oral squamous cell carcinoma

BACKGROUND

Early-stage oral squamous cell carcinoma (OSCC) patients have a one-in-four risk of regional metastasis (LN+), which is also the most significant prognostic factor for survival. As there are no validated biomarkers for predicting LN+ in early-stage OSCC, elective neck dissection often leads to over-treatment and under-treatment. We present a machine-learning-based model using the quantitative nuclear phenotype of cancer cells from the primary tumor to predict the risk of nodal disease.

METHODS AND FINDINGS

Tumor specimens were obtained from 35 patients diagnosed with primary OSCC and received surgery with curative intent. Of the 35 patients, 29 had well (G1) or moderately (G2) differentiated tumors, and six had poorly differentiated tumors. From each, two consecutive sections were stained for hematoxylin & eosin and Feulgen-thionin staining. The slides were scanned, and images were processed to curate nuclear morphometric features for each nucleus, measuring nuclear morphology, DNA amount, and chromatin texture/organization. The nuclei (n = 384,041) from 15 G1 and 14 G2 tumors were randomly split into 80% training and 20% test set to build the predictive model by using Random Forest (RF) analysis which give each tumor cell a score, NRS. The area under ROC curve (AUC) was 99.6% and 90.7% for the training and test sets, respectively. At the cutoff score of 0.5 as the median NRS of each region of interest (n = 481), the AUC was 95.1%. We then developed a patient-level model based on the percentage of cells with an NRS ≥ 0.5. The prediction performance showed AUC of 97.7% among the 80% (n = 23 patient) training set and with the cutoff of 61% positive cells achieved 100% sensitivity and 91.7% specificity. When applying the 61% cutoff to the 20% test set patients, the model achieved 100% accuracy.

CONCLUSIONS

Our findings may have a clinical impact with an easy, accurate, and objective biomarker from routine pathology tissue, providing an unprecedented opportunity to improve neck management decisions in early-stage OSCC patients.

Expression of microRNA-21 in saliva and tumor tissue of patients with oral squamous cell carcinoma: a predictor of cervical lymph node metastasis

OBJECTIVE

Evaluation of diagnostic accuracy of microRNA-21 (miR-21) in saliva and tumor tissue for presurgical assessment of lymph node metastasis in patients with oral squamous cell carcinoma (OSCC).

STUDY DESIGN

Unstimulated whole saliva and tumor tissue was obtained from clinically suspected patients with OSCC. A total of 130 patients diagnosed with OSCC were included as study participants. The assessment of cervical lymph node metastasis was done before surgery using imaging scans and post surgically confirmed by histopathologic examination of excised lymph nodes. miR-21 expression was evaluated using real-time polymerase chain reaction. The data was statistically analyzed for correlation analysis, cutoff values, sensitivity, and specificity. The κ statistic was applied to assess the degree of agreement between the lymph node metastasis and miR-21 expression.

RESULTS

miR-21 expression showed a statistically significant correlation with cervical lymph node metastasis with a diagnostic accuracy of 65% to 71.54% in saliva and 69% to 81.54% in tumor tissue. Very good agreement was observed between tumor tissue miR-21-3p and cervical lymph node metastasis with a specificity of 80.60% and a sensitivity of 82.40%.

CONCLUSIONS

miR-21 expression in saliva and tumor tissue of patients with OSCC showed high diagnostic accuracy for assessment of cervical lymph node metastasis. It can be used as an alternative for assessment of cervical lymph node metastasis before surgery.

Pulmonary MicroRNA Changes Alter Angiogenesis in Chronic Obstructive Pulmonary Disease and Lung Cancer

The pulmonary endothelium is dysfunctional in chronic obstructive pulmonary disease (COPD), a known risk factor for lung cancer. The pulmonary endothelium is altered in emphysema, which is disproportionately affected by cancers. Gene and microRNA expression differs between COPD and non-COPD lung. We hypothesised that the alteration in microRNA expression in the pulmonary endothelium contributes to its dysfunction. A total of 28 patients undergoing pulmonary resection were recruited and endothelial cells were isolated from healthy lung and tumour. MicroRNA expression was compared between COPD and non-COPD patients. Positive findings were confirmed by quantitative polymerase chain reaction (qPCR). Assays assessing angiogenesis and cellular migration were conducted in Human Umbilical Vein Endothelial Cells (n = 3-4) transfected with microRNA mimics and compared to cells transfected with negative control RNA. Expression of miR-181b-3p, miR-429 and miR-23c (all p < 0.05) was increased in COPD. Over-expression of miR-181b-3p was associated with reduced endothelial sprouting (p < 0.05). miR-429 was overexpressed in lung cancer as well and exhibited a reduction in tubular formation. MicroRNA-driven changes in the pulmonary endothelium thus represent a novel mechanism driving emphysema. These processes warrant further study to determine if they may be therapeutic targets in COPD and lung cancer.

Contribution of Genomics to the Surgical Management and Study of Oral Cancer

Background

Oral squamous cell carcinoma (OSCC) is the most frequent type of tumor arising from the oral cavity. Surgery is the cornerstone of the treatment of these cancers. Tumor biology has long been overlooked as an important contributor to the outcome of surgical procedures, but recent studies are challenging this concept. Molecular analyses of tumor DNA or RNA provide a rich source of information about the biology of OSCC.

Methods

We searched for relevant articles using PubMed. We examined in particular the prospect of applying molecular methods for minimally invasive exploration of OSCC biology.

Results

We examined five potential applications of genomics to the surgical management and study of OSCC: i) assessing oral potentially malignant lesions; ii) tumor staging prior to surgery; iii) predicting postoperative risk in locally advanced tumors; iv) measuring minimal residual disease and optimizing the longitudinal monitoring of OSCC; and v) predicting the efficacy of medical treatment.

Conclusions

Genomic information can be harnessed in order to identify new biomarkers that could improve the staging, choice of therapy and management of OSCC. The identification of new biomarkers is awaited for better personalization of the surgical treatment of OSCC.

MicroRNA expression profile in patients with cystic echinococcosis and identification of possible cellular pathways

Cystic echinococcosis (CE) is a neglected tropical disease, caused by metacestode (larval) form of the Echinococcus granulosus sensu lato (sl) in humans. MicroRNAs (miRNAs) are small, stable, tissue-specific RNA molecules encoded by the genome that are not translated into proteins. Circulating miRNA expression profiles vary in health and disease. The aim of this study is to determine the altered cellular pathways in CE by comparing the miRNA profiles of controls and CE patients with active or inactive cysts. Following abdominal ultrasonography (US) examination, 20 patients diagnosed with active CE (CE1, CE2, CE3a and CE3b) or inactive CE (CE4 and CE5) and three healthy controls were included in the study. The expression profiles of 372 biologically relevant human miRNAs were investigated in serum samples from CE patients and healthy controls with miScript miRNA HC PCR Array. Compared with the control group, expression of 6 miRNAs (hsa-miR-4659a-5p, hsa-miR-4518, hsa-miR-3977, hsa-miR-4692, hsa-miR-181b-3p, hsa-miR-4491) and one miRNA (hsa-miR-4687-5p) were found to be downregulated in CE patients with active and inactive cysts, respectively (p < 0.05). For downregulated miRNAs in this study, predicted targets were found to be associated mainly with cell proliferation, apoptosis, cell-cell interactions and cell cycle regulation. Further studies in this direction may elucidate the pathogenesis of human CE and the relationship between CE and other pathologies.