MicroRNA Expression Profiling of Cutaneous Squamous Cell Carcinomas Arising in Different Sites

Study on serum miR-182 as a marker for diagnosis and prognosis of cervical cancer

BACKGROUND

Cervical cancer (CC) is a common female malignancy, with a global incidence rate second only to breast cancer.

OBJECTIVE

To propose a new idea for early treatment and auxiliary diagnosis of CC by exploring the diagnostic and prognostic implications of serum miR-182 in CC.

METHODS

We enrolled 70 CC patients, 35 cervical intraepithelial neoplasia (CIN) patients and 35 healthy controls (HCs), who visited The First Affiliated Hospital of Hainan Medical College Hospital between January 2015 and April 2016. miR-182 expression was quantified by real-time quantitative PCR and compared among the three groups. The correlation of serum miR-182 expression with patients' clinical features was evaluated. The receiver operating characteristic curve (ROC) and the Kaplan-Meier method were used to evaluate the early diagnostic value and prognostic value of serum miR-182. Cox regression analysis was performed to determine serum miR-182 expression and its important role in predicting CC patients' prognosis.

RESULTS

Serum miR-182 expression was determined to be 0.345 ± 0.094, 0.369 ± 0.076, and 0.586 ± 0.157 in CC patients, CIN patients, and HCs, respectively (P< 0.001). Serum miR-182 expression had an obvious association with lymph node metastasis and pathological differentiation (P< 0.05). The area under the ROC curve (AUC) of serum miR-182 was 0.709 (95% CI: 0.622-0.795), the critical value was 0.456, the sensitivity was 81.4%, and the specificity was 52.9%. CC patients were grouped as either the low- (miR-182 < 0.3) or high-level group (miR-182 ⩾ 0.03) based on serum miR-182 levels, and a Cox regression model of OS was established. Serum miR-182 expression was identified as a factor independently influencing CC patients' OS (P= 0.028); the death risk of the high-level group was 3.246 times that of the low-level group.

CONCLUSION

Serum miR-182 expression is not only a biomarker for early diagnosis of CC, but also one of the independent factors influencing the survival and prognosis of CC patients.

MicroRNA Expression Profile Separates Squamous Cell Carcinoma by Mode of Differentiation

BACKGROUND

Squamous cell carcinoma (SCC) is a non-melanoma skin cancer with several risk factors including age and sun exposure. The degree of histological differentiation is considered an independent predictor of recurrence, metastasis, and survival. MicroRNAs (miRNAs) are small non-coding RNAs that play an important role in regulating gene expression, culminating in the initiation and progression of multiple tumors. The aim of this study was to determine changes in miRNA expression as a result of the mode of differentiation in SCC.

METHODS

We analyzed 29 SCC samples that were separated by mode of differentiation into well (n=4), moderate (n=20) and poor (n=5). Of the 29 samples, five had matched normal tissues, which were used as controls. Total RNA was extracted using the RNeasy FFPE kit, and miRNAs were quantified using Qiagen MiRCURY LNA miRNA PCR Assays. Ten miRNAs (hsa-miR-21, hsa-miR-146b-3p, hsa-miR-155-5p, hsa-miR-451a, hsa-miR-196-5p, hsa-miR-221-5p, hsa-miR-375, hsa-miR-205-5p, hsa-let-7d-5p and hsa-miR-491-5p) that have been previously differentiated in cancer, were quantified. A fold regulation above 1 indicated upregulation and below 1, downregulation.

RESULTS

Hierarchical clustering showed that the miRNA expression profile in the moderately differentiated group was similar to the well-differentiated group. The miRNA with the greatest upregulation in the moderate group was hsa-miR-375, while in the well group, hsa-miR-491-5p showed the greatest downregulation.

CONCLUSION

In conclusion, this study observed that the well and moderate groups had similar microRNA expression patterns compared to the poorly differentiated group. MicroRNA expression profiling may be used to better understand the factors underpinning mode of differentiation in SCC.

MicroRNA31 and MMP-1 contribute to the differentiated pathway of invasion -with enhanced epithelial-to-mesenchymal transition- in squamous cell carcinoma of the skin

Epithelial to mesenchymal transition (EMT) is an important mechanism of invasion in cutaneous squamous cell carcinomas (cSCCs) and has been found to be enhanced in tumors originated from actinic keratosis with transformation limited to the basal epithelial layer -differentiated pathway-, compared to cases with invasion subsequent to complete epidermal transformation -classical pathway-. Several microRNAs and proteins can contribute to EMT modulation in cSCCs. MicroRNA21 and microRNA31 are involved in posttranscriptional regulation of protein expression and could play a relevant role in EMT and cSCC progression. Throughout the EMT process upregulation of matrix metalloproteinases (MMPs) enhances invasiveness and MMP-1 and MMP-3 contribute to local invasion, angiogenesis and metastasis in cSCCs. Additionally, cSCC development is associated with PTEN loss and NF-κB, NOTCH-1 and p63 activation. The aim of this work is to identify differences in the expression of those molecules between both pathways of cSCCs development. Eight tissue microarrays from 80 consecutive cSCCs were analyzed using LNA-based miRNA in situ hybridization for miRNA21 and miRNA31 evaluation, and immunohistochemistry for MMP-1, MMP-3, PTEN, NOTCH-1, NF-κB, p63 and CD31. Significantly higher expression of miRNA31 (p < 0.0001) and MMP-1 (p = 0.0072) and angiogenesis (p = 0.0199) were found in the differentiated pathway, whereas PTEN loss (p = 0.0430) was more marked in the classical pathway. No significant differences were found for the other markers. Our findings support a contribution of miRNA31 and MMP-1 in the differentiated pathway, associated to EMT and increased microvascularization. The greater PTEN loss in the classical pathway indicate that its relevance in cSCC is not EMT-related.